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1
Schramm, Benítez Isabella Citlalli. "Defect-engineered (Ti,Al)N thin films." Doctoral thesis, Linköpings universitet, Nanostrukturerade material, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-142116.
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This thesis investigates the effect of point defects (nitrogen vacancies and interstitials) and multilayering ((Ti,Al)N/TiN) on the phase transformations in cathodic arc-evaporated cubic (Ti,Al)N thin films at elevated temperatures. Special attention is paid to the evolution of the beneficial spinodal decomposition into c-TiN and c-AlN, the detrimental formation of wurtzite AlN and the potential application as hard coating in cutting tools. c-(Ti1-xAlx)Ny thin films with varying Al fractions and N content (y = 0.93 to 0.75) show a delay in the spinodal decomposition when increasing the amount of N vacancies. This results in a 300 °C upshift in the age hardening and a delay in the w-AlN formation, while additions of self-interstitials enhance phase separation. High temperature interaction between hard metal substrates and thin films is more pronounced when increasing N deficiency through diffusion of substrate elements into the film. Low N content films (y = 0.58 to 0.40) showed formation of additional phases such as Ti4AlN3, Ti2AlN, Al5Ti2 and Al3Ti during annealing and a transformation from Ti2AlN to Ti4AlN3 via intercalation. The multilayer structure of TiN/TiAlN results in surfacedirected spinodal decomposition that affects the decomposition behavior. Careful use of these effects appears as a promising method to improve cutting tool performance.Diese Arbeit untersucht den Effekt von Punktdefekten (Stickstoffleerstellen und Zwischengitteratome) und Multilagen ((Ti,Al)N/TiN) auf die Phasenumwandlung in lichtbogenverdampften kubischen (Ti,Al)N-Dünnschichten bei erhöhten Temperaturen. Besonderes Augenmerk liegt auf der Entwicklung der vorteilhaften spinodalen Entmischung in c-TiN und c-AlN und der nachteiligen Bildung von Wurtzit-AlN, sowie der möglichen Anwendung als Hartstoffbeschichtung von Schneidwerkzeugen. c-(Ti1-xAlx)Ny mit unterschiedlichem Al-Anteil und N-Gehalten von y = 0,93 bis 0,75 zeigt mit zunehmenden Stickstoffleerstellen eine Verzögerung der spinodalen Entmischung. Dadurch verschiebt sich die Ausscheidungshärtung um 300 °C zu höheren Temperaturen und die w-AlN-Bildung wird verzögert, während der Einbau von Eigenzwischengitteratomen die Entmischung beschleunigt. Die Hochtemperaturwechselwirkung zwischen Hartmetallsubstrat und Dünnschicht durch Diffusion von Substratelementen in die Schicht nimmt mit steigendem Stickstoffdefizit zu. Stickstoffarme Schichten (y = 0,58 bis 0,40) zeigen während der Wärmebehandlung zusätzliche Phasen wie Ti4AlN3, Ti2AlN, Al5Ti2 und Al3Ti und eine Umwandlung von Ti2AlN in Ti4AlN3 durch Interkalation. Die Multischichtstruktur von TiN/TiAlN führt zu einer oberflächengerichteten spinodalen Entmischung, die das Entmischungsverhalten beeinflusst. Ein gezielter Einsatz dieser Effekte erscheint als ein vielsprechender Weg, um die Leistungsfähigkeit von Schneidwerkzeugen zu verbessern.
I denna avhandling behandlas inverkan av punktdefekter (kvävevakanser och interstitialer) och multilagring ((Ti,Al)N/TiN) på högtemperaturfasomvandlingar i tunna arcförångade skikt av kubiska (Ti,Al)N. Störst vikt har lagts på utvecklingen av det fördelaktiga spinodala sönderfallet till c-TiN och c-AlN, den ofördelaktiga omvandlingen till w-AlN och potentialen som hårda skikt i verktygstillämpningar. Tunna c-(Ti1-xAlx)Ny skikt med olika Al-andel och en N-halt mellan (y = 0.93 och 0.75) uppvisar ökad undertryckning av det spinodala sönderfallet med ökat kvävevakanshalt. Detta resulterar i bildandet av w-AlN skiftas upp i temperatur vilket gör att åldershärdningen höjs med 300 °C. Däremot medför närvaron av självinterstitialer ett snabbare sönderfall. Växelverkan mellan hårdmetallsubstraten och de tunna skikten vid hög temperatur ökar med minskad kvävehalt i skiten genom diffusion av atomer från substratet in i filmen. Filmer med låg kvävehalt (y = 0.58 till 0.40) bildar även andra faser så som Ti4AlN3, Ti2AlN, Al5Ti2 och Al3Ti under värmebehandling och fasomvandlingen från Ti2AlN till Ti4AlN3 sker via en mekanism kallad intercalation. Multilagring av TiN/TiAlN resulterar i ett ytriktad spinodalt sönderfall vilket påverkar det totala sönderfallsförloppet. Nyttjande av dessa resultat syns som lovande vägar till förbättrade verktygsegenskaper.
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Qangule, Lusanda Lungelwa. "Investigation of the ⁵¹V(n,d)⁵⁰Ti reaction." Master's thesis, University of Cape Town, 1992. http://hdl.handle.net/11427/18346.
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Includes bibliography.The ⁵¹V(n,d) ⁵⁰Ti reaction has been studied with neutrons of energy of 21.6 MeV. The measurement of the angular distribution of the differential cross section was made with the aid of a spectrometer designed by Dr. McMurray and Prof K. Bharuth - Ram. The spectrometer consists of three multiwire proportional counters followed by a curved plastic scintillator. The proportional counters act as ΔE detectors and the scintillator acts as an energy detector. The ΔE - E method based on the Bethe - Bloch formula was used for particle identification. The spectrometer allows accumulation of data over an angle range of ≥ 70°, has angular resolution (FWHM) ≈ 5° and energy resolution (FWHM) ≈ 0.8 MeV. A review of the optical model and the reaction mechanism is presented. Theoretical DWBA cross sections are performed by using the Distorted Waves code DWUCK4. Spectroscopic factors for transitions to the 0⁺, 2⁺ and (4⁺ , 6⁺ ) states in ⁵⁰Ti have been determined from the comparison of experimental differential cross sections to theoretical DWBA differential cross sections. These have a mean value of 0.42, 0.30 and 0.38 respectively. The spectroscopic factors are compared with the results from (e,e' p) and (d,³He) measurements and shell model calculations.
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Basilio, Bartolo Juan Carlos, and Prada Renzo Jos? Mendoza. "Gesti?n de requerimientos del ?rea de TI." Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2012. http://hdl.handle.net/10757/300089.
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La gesti?n de requerimientos del ?rea de TI en la empresa Laboratorios Elifarma es el tema principal de la presente tesis. El presente documento ha sido dividido en tres cap?tulos, modelado de procesos, aplicaci?n de m?todos agiles y CMMi. El modelado de procesos, comprende el an?lisis de la situaci?n actual de la empresa e implementaci?n de mejoras a los procesos, para poder medirlas se establecen indicadores que faciliten su gesti?n. En la segunda parte, se incorporan practicas agiles al proceso actual con la finalidad de optimizarlos en tiempo y costo. Como ?ltimo punto se incorporan pr?cticas espec?ficas y gen?ricas de CMMi, alineando los procesos al marco establecido con la finalidad de conseguir resultados de calidad que aporten valor a la empresa.Tesis
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Krüger, Kathrin [Verfasser], and Dr S. [Akademischer Betreuer] Ulrich. "Funktionelle PVD-Viellagenschichten aus den Systemen Fe-Co-Hf-N, Ti-N und Ti-Al-N für die Hochfrequenz-Sensorik / Kathrin Krüger. Betreuer: Dr. S. Ulrich." Karlsruhe : KIT-Bibliothek, 2015. http://d-nb.info/1070635707/34.
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Salamat, N. "High pressure solid state chemistry of C-N-H and Ti-N systems." Thesis, University College London (University of London), 2010. http://discovery.ucl.ac.uk/20191/.
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This thesis presents the use of molecular precursors for the synthesis of solid-state materials through the application of extreme conditions. The main tool for the exploration of these materials was the diamond anvil cell which generated static pressures of up to 85 GPa. Combined with the use of highpower lasers, it provides a powerful and efficient technique for high-pressurehigh- temperature synthesis of solid-state materials. The work presented here is an investigation into the synthesis and recovery of new materials within two solid-state systems, C-N-H and Ti-N-O. Crystallographic analysis of these systems is a challenging process, made more difficult by their relatively light elemental composition and the use of the diamond anvil cell. In both cases a systematic experimental and analytical strategy was adopted to enable the extraction of the best data possible, both qualitatively and statistically. Two C-N-H systems were investigated: C2N3H and C6N9H3.HCl. Synchrotron X-ray diffraction and Raman scattering data are reported for the new dense tetrahedrally bonded phase C2N3H with a defective wurtzite structure. This is synthesised by laser heating from an organic precursor, dicyandiamide, C2N4H4 at high-pressure in a diamond anvil cell. This work confirms the structure deduced in previous work from electron diffraction experiments on samples recovered to ambient conditions. The graphitic layered compound C6N9H3.HCl was subjected to pressures up to 70 GPa in a diamond anvil cell and its structural behaviour was examined using synchrotron X-ray diffraction. The use of laser heating experiments revealed the synthesis of a new carbon nitride phase which is recoverable to ambient conditions. The second group of systems explored was those based on Ti-O-N. Amorphous or nano-crystalline precursors were used to attempt the synthesis of Ti3N4. The high-pressure and temperature behaviour of these materials was examined using synchrotron X-ray diffraction and Raman spectroscopy, in a laser-heated diamond anvil cell. In addition, the high-pressure studies of Ti2.85O4N, a recently discovered titanium oxynitride phase, are reported here up to 70 GPa. Using synchrotron angle dispersive techniques two high-pressure phases are observed and an attempt to elucidate these structures are reported.
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Flink, Axel. "Growth and Characterization of Ti-Si-N Hard Coatings." Licentiate thesis, Linköping : Department of Physics, Chemistry and Biology, Linköping University, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-7741.
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Flink, Axel. "Growth and Characterization of Ti-Si-N Thin Films." Doctoral thesis, Linköpings universitet, Tunnfilmsfysik, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-11929.
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Utvecklingen inom materialforskningen går mot att framställa avancerade material vilka är skräddarsydda för olika tillämpningar. Detta har medfört att det blir allt mer populärt att belägga ytor med ett eller flera tunna lager med syfte att förbättra materialegenskaperna. Användningsområden för ytbeläggningar går att hitta inom allt från vardagliga produkter såsom teflonbeläggningar av stekpannor, förgyllning av smycken till avancerad halvledarteknik för att åstadkomma energieffektiva lysdioder. Det enskilt största tillämpningsområdet för tunna filmer är dock som skyddande skikt för verktyg inom skärande bearbetning. Utvecklingen går stadigt mot högre skärhastigheter och därmed ökade temperaturer, idagsläget kan området där verktyget och arbetsmaterialet är i kontakt nå temperaturer på mellan 800-1000 °C utan att förlora nämnvärt i styrka. Detta har gjorts möjligt genom att belägga skären med någon eller några μm (tusendels mm) av lämpligt keramiskt material i avseende att öka motståndskraften för nötning vid bearbetning vid höga temperaturer. I den här avhandlingen har tunna filmer studerats med det övergripande målet att förbättra egenskaper hos verktyg för skärande metallbearbetning genom att öka motståndskraften hos materialen mot mekanisk och kemisk nötning vid höga temperaturer. Materialsystemet som undersökts är Ti-Si-N, där tunna filmer av både legeringar och tvåfassystem har syntetiserats och egenskapskarakteriserats. Legeringarna är belagda med varierande Si-halt från 0 till 10 atomprocent och avsedda för att studera strukturella, termiska och mekaniska egenskaper. De framställdes med en teknik som kallas arcförångning, där man i ett vakuumsystem frigör högenergetiskt material i det här fallet av Ti och Si som förångas från en solid yta kallad target. Atomerna joniseras genom kollisioner med elektroner och reagerar på sin väg mot substratet med kvävgas. Väl framme vid substratet, kondenserar jonerna och bilder den tunna filmen. Filmerna består av två strukturtyper, den första är en fast lösning där Si atomer upp till 5 at.% ersätter Ti atomer i TiN. I det andra fallet så segregerar Si till korngränserna. Värmebehandlingsexperiment visar att Si bildar SiNx som kapslar in TiN-korn vid temperaturer upp till 1000 °C. Hårdhetstester visar att filmerna bibehåller sin hårdhet upp till 1000 °C tack vare fasomvandlingen. Även vid 1100 °C är hårdheten hög. Dessa skikt besitter alltså egenskaper som gör dem väldigt användbara inom tillämpningar för skärande bearbetning. Nanostrukturerade materials egenskaper beror på dess mikrostruktur snarare än på de grundämnen som ingår, detta exemplifieras av TiN-SiNx-nanokompositer bestående av nanokristallina TiN-korn inbäddade i några få atomlager SiNx, där materialegenskaperna helt och hållet beror på kornstorleken på TiN-kornen och tjockleken på SiNx-lagren. Ökas tjockleken på SiNx minskar hårdheten. Dessa filmer har mycket goda mekaniska egenskaper och är ett av de hårdaste materialen som finns. Nyckeln till den höga hårdheten hos skikten ligger i att bilda starka bindningar mellan TiN och SiNx. Hur dessa ser ut vet man dock inte eftersom strukturen på SiNx gränsytan inte är känd. Anledningen är att den är svår att avbilda på grund av dess krökta form och begränsade volym. I denna avhandling har TiN/SiNx multilager belagts, dvs. en lagrad struktur TiN alternerad med SiNx. Dessa filmer framställdes med sputtring, en teknik som liknar arcförångning men där man istället accelerera positivt laddade joner mot Ti och Si targets med en hög negativ potential som frigör Ti och Si. I multilagren varierades SiNx-lagrets tjocklek mellan endast några få atomlager för att göra en förenklad modell av gränsytan hos nanokompositen och med atomupplöst transmissionselektronmikroskopi samt hårdhetsmätningar konstateras sedan att de hårdaste filmerna var de där kristallin SiNx stabiliseras mellan TiNkorn. Vidare studerar jag SiNx/TiN ytor med sveptunnelmikroskopi och täthetsfunktionalteori (en kvantmekanisk simuleringsmetod). Mina resultat visar SiNx och bindningarna till TiN är mycket mer komplicerade än vad man tidigare trott, då de kan vara kristallina och anta komplexa rekonstruktioner. Detta bidrar till den starka bindningen mellan TiN och SiNx vilket i sin tur förklarar varför materialen blir så hårda.Ti-Si-N and Ti-Al-Si-N thin solid films have been studied by analytical electron microscopy, X-ray diffraction, scanning tunneling microscopy, X-ray photoelectron spectroscopy, elastic recoil detection analysis, nanoindentation, and ab initio calculations. I find that arc evaporated (Ti1-xSix)Ny films can be grown as cubic solid solutions up to x = 0.09 with a dense columnar microstructure. Films with higher Si content up to x = 0.20 assumes an extremely defect-rich, feather-like structure consisting of cubic TiN:Si nanocrystallite bundles with low-angle grain boundaries caused by thermodynamically driven Si segregation. Correspondingly, the N content in the films increases close to linear with the Si content from y = 1.00 (x = 0) to y = 1.13 (x = 0.20). Annealing of the films at 1000 °C yields a metastable crystalline SiNz (1.0 ≤ z ≤ 1.33) tissue phase in 0.04 ≤ x ≤ 0.20 films which is (semi)-coherent to TiN. These films are compositionally stable and exhibit retained hardness between 31-42 GPa up to 1000 °C. At 1100-1200 °C, the tissue phase amorphizes and all SiNz diffuse out of the films, followed by recrystallization of the cubic phase. Hard turning testing was performed on (Ti0.83Si0.17)N1.09. Analysis of the tool-chip interface prepared by focused ion beam revealed shear deformation in the film and an adhering layer consisting of the work-piece material and Si and N from the film. For (Ti0.33Al0.67)1-xSix)N (0 ≤ x ≤ 0.29) films the NaCl structure cubic (Ti,Al)N solid solution phase is predominant at low Si contents, which gradually changes to a dominating hexagonal wurtzite (Al,Ti,Si)N solid solution for 0.04 ≤ x ≤ 0.17. Additional Si results in amorphization. Annealing experiments at 600-1000 °C yields spinodal decomposition of c-(Al,Ti)N into c-AlN and c-TiN, with corresponding age hardening. The h-(Al,Ti,Si)N films exhibit precipitation of c- TiN with smaller volume than the host lattice, which results in tensile cracks formations and age hardening. Films with c-(Ti,Al)N perform best in turning applications, while films with h- (Al,Ti,Si)N form cracks and fail. Finally, I have characterized the nature of metastable crystalline SiNz phases and the interface between TiN(001) and SiNz. Magnetron sputtering was used to deposit TiN/SiNz(001) nanolaminate films with varying SiNz and TiN layer thicknesses. Maximum hardness is obtained when SiNz forms coherent interfaces with TiN. In addition, in situ surface analyses in combination with ab-initio calculations reveal that SiNz sub-monolayers grow epitaxially and form crystalline reconstructions on TiN(001) and TiN(111) surfaces. Phonon calculations predict that stoichiometric c-SiN is dynamically instable when the atoms are arranged in the NaCl and ZnS forms. However, c-Si3N4 can be stabilized with D022 or L12 ordered ZnS-like structures. These results have impact for the design of superhard nanocomposites and multilayer thin films.
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Rahil, Issam. "Elaboration et caractérisation de revêtements à base de nitrure de chrome, carbonitrure et carbure de titane élaborés par pulvérisation magnétron." Phd thesis, Ecole nationale supérieure d'arts et métiers - ENSAM, 2013. http://pastel.archives-ouvertes.fr/pastel-00967251.
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Le but de ce travail est d'élaborer de nouveaux revêtements anti-usure à base de nitrure de chrome, de carbure et de carbonitrure de titane par dépôt physique en phase vapeur afin d'améliorer la résistance à l'usure à sec des outils de coupe du bois.Des revêtements binaires de CrN et de MoN, ternaires de Cr-Mo-N et de Ti-W-C et quaternaires de Ti-W-C-N ont été déposés sur des outils de coupe en carbure de tungstène et en acier et sur des substrats de silicium par pulvérisation magnétron RF en utilisant différentes cibles (Cr, Mo, Ti et WC) sous différentes atmosphères (Ar, Ar + N2, Ar + CH4 et Ar + N2 + CH4).L'influence de la pression de travail, des ratios des gaz plasmagènes, des tensions d'auto-polarisation des cibles, de la température des substrats et de celle du recuit sur les propriétés des revêtements ont été étudiées, en utilisant l'EDS, la WDS, l'XPS, la DRX, le MEB, le MET, l'AFM, la microscopie optique, l'interférométrie optique (2D et 3D), le Scratch test, l'essai Daimler, la nanoindentation et la tribométrie alternative et rotative. L'objectif est d'établir une corrélation entre le comportement tribologique des revêtements étudiés et leurs propriétés physico-chimiques et mécaniques.Les revêtements optimaux présentant la meilleure résistance à l'usure à sec ont été testés en usinage de l'épinette noire à l'échelle industrielle dans des conditions sévères (-20/-25 °C). Les résultats montrent que grâce à l'emploi des revêtements de Cr-Mo-N, Ti-W-C et de Ti-W-C-N, la durée de vie des outils coupants a été augmentée de 47 à 77 % par rapport à l'outil non revêtu.Mots clés: revêtement, (Cr-Mo)N, (Ti-W)(C,N), propriétés physico-chimiques, propriétés mécaniques, comportement tribologique, usinage bois
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Dümmler, Wolfram. "Étude par spectrométrie de masse d'ions secondaires des interfaces Ti/Si₃N₄, Ag/Si₃N₄ et Cu/Si₃N₄." Vandoeuvre-les-Nancy, INPL, 1998. http://www.theses.fr/1998INPL046N.
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Les interfaces céramique/métal et leur évolution au cours de traitements thermiques ont été étudiées. Les constituants majeurs des brasures, titane, argent et cuivre, ont été déposés par évaporation et pulvérisation cathodique sur Si₃N₄ poli. Les zones de réactions étant à l'échelle nanométrique, la spectrométrie de masse des ions secondaires (SIMS) est une technique bien adaptée permettant d'obtenir les profils des concentrations des éléments en fonction de la profondeur. Ce travail est centré sur l'étude des possibilités du SIMS utilisant une source de césium pour le bombardement ionique avec détection des molécules MCs+. Nous avons étayé les résultats SIMS par l'emploi de façon complémentaire de SNMS, AES, MEB, DRX et AFM. Contrairement à l'argent et le cuivre, le titane mouille bien la céramique et une couche intermédiaire se forme à l'interface Ti/Si₃N₄. Après des discussions sur les phénomènes qui altèrent la résolution en profondeur d'une analyse SIMS, les calculs de correction sur les coefficients de diffusion D obtenus donnent D ≈ 0,8. . . 2. 10-²⁰ m²/s entre 600°C et 700°C. La pénétration du titane dans la céramique étant très faible, ce sont plutôt des réactions chimiques dans la région interfaciale qui assurent la bonne liaison. Lors des traitements thermiques des échantillons Ag/Ti/ Si₃N₄ et Cu/Ti/ Si₃N₄, on constate un mélange complet des phases avec des réactions complexes dans le cas de Cu/Ti/ Si₃N₄. Pour Ag/Ti/ Si₃N₄, les réactions sont beaucoup moins nombreuses et les phases restent plus pures et bien séparées les unes des autres.
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Höglund, Carina. "Growth and Phase Stability Studies of Epitaxial Sc-Al-N and Ti-Al-N Thin Films." Doctoral thesis, Linköpings universitet, Tunnfilmsfysik, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-56274.
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¨This Thesis treats the growth and characterization of ternary transition metal nitride thin films. The aim is to probe deep into the Ti-Al-N system and to explore novel Sc-Al-N compounds. Thin films were epitaxially grown by reactive dual magnetron sputtering from elemental targets onto single-crystal substrates. Ion beam analyses were used for compositional analysis and depth profiling. Different X-ray diffraction techniques were employed, ex situ using Cu radiation and in situ during deposition using synchrotron radiation, to achieve information about phases, texture, and thickness of films, and to follow roughness evolution of layers during and after growth. Transmission electron microscopy was used for overview and lattice imaging, and to obtain lattice structure information by electron diffraction. In the Sc-Al-N system, the perovskite Sc3AlN was for the first time synthesized as a thin film and in single phase, with a unit cell of 4.40 Å. The hardness was found to be 14.2 GPa, the elastic modulus 21 GPa, and the room temperature resistivity 41.2 μΩcm. Cubic solid solutions of Sc1-xAlxN can be synthesized with AlN molar fraction up to ~60%. Higher AlN contents yield three different epitaxial relations to ScN(111), namely, #1 Sc1-xAlxN(0001) || ScN(111) with Sc1-xAlxN[11210] || ScN[110], #2 Sc1-xAlxN(1011) || ScN(110) with Sc1-xAlxN[1210] || ScN[110], and #3 Sc1-xAlxN(1011) || ScN(113). An in situ deposition and annealing study of cubic Sc0.57Al0.43N films showed volume induced phase separation into ScN and wurtzite structure AlN, via nucleation and growth at the domain boundaries. The first indications for phase separation are visible at 1000 °C, and the topotaxial relationship between the binaries after phase separation is AlN(0001) || ScN(001) and AlN<01ɸ10> || ScN <1ɸ10>. This is compared with Ti1-xAlxN, for which an electronic structure driving force leads to spinodal decomposition into isostructural TiN and AlN already at 800 °C. First principles calculations explain the results on a fundamental physics level. Up to ~22% ScN can under the employed deposition conditions be dissolved into wurtzite Sc1-xAlxN films, while retaining a single-crystal structure and with lattice parameters matching calculated values. In the Ti-Al-N system, the Ti2AlN phase was synthesized epitaxially by solid state reaction during interdiffusion between sequentially deposited layers of AlN(0001) and Ti(0001). When annealing the sample, N and Al diffused into the Ti layer, forming Ti3AlN(111) at 400 ºC and Ti2AlN(0001) at 500 ºC. The Ti2AlN formation temperature is 175 ºC lower than earlier reported results. Another way of forming Ti2AlN phase is by depositing understoichiometric TiNx at 800 °C onto Al2O3(0001). An epitaxial Ti2Al(O,N) (0001) oxynitride forms close to the interface between film and substrate through a solid state reaction. Ti4AlN3 was, however, not possible to synthesize when depositing films with a Ti:Al:N ratio of 4:1:3 due to competing reactions. A substrate temperature of 600 ºC yielded an irregularly stacked Tin+1AlNn layered structure because of the low mobility of Al ad-atoms. An increased temperature led to Al deficiency due to outdiffusion of Al atoms, and formation of the Ti2AlN phase and a Ti1-xAlxN cubic solid solution.
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McArthur, Warren F. "Ti-Si-N as a Cu diffusion barrier in microelectronic metallization /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 1999. http://wwwlib.umi.com/cr/ucsd/fullcit?p9938292.
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Chacon, Maria Lu?za Assun??o. "A personagem ensimesmada em Tu n?o te moves de ti." PROGRAMA DE P?S-GRADUA??O EM ESTUDOS DA LINGUAGEM, 2015. https://repositorio.ufrn.br/jspui/handle/123456789/22368.
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Esta pesquisa pretende analisar a obra Tu n?o te moves de ti (1980), de Hilda Hilst (1930-2004). Em nossa investiga??o, observaremos primordialmente a complexidade do comportamento das personagens. ? importante destacar, no entanto, que o fato de a personagem ser a categoria principal de nossa an?lise n?o implica na exclus?o de outros elementos da narrativa. Detectamos que a personagem, elemento mais atuante da fic??o, encontra-se radicalmente ensimesmada no texto hilstiano, e ? sobre esse aspecto que pretendemos nos deter. Sendo assim, investigaremos a rela??o estabelecida entre a subjetividade exacerbada das personagens e a linguagem utilizada pela autora. Para tanto, observaremos o recurso discursivo que ? bastante recorrente em seus textos: o fluxo da consci?ncia. Refletir acerca desse recurso ? de fundamental import?ncia para a nossa pesquisa, pois a problematiza??o do indiv?duo, na escrita de Hilst, passa tamb?m pelo desordenamento da linguagem. ? v?lido ressaltar, ainda, que consideraremos o contexto social no qual a obra se insere, promovendo di?logos entre ambos a fim de evidenciar de que forma a sociedade se configura no romance. Em fun??o disso, n?o entenderemos o isolamento das personagens somente em sua dimens?o ontol?gica, mas tamb?m em sua dimens?o hist?rica e social.
Esta pesquisa pretende analizar la obra Tu n?o te moves de ti (1980), de Hilda Hilst (1930-2004). En nuestra investigaci?n, observaremos primordialmente la complejidad del comportamiento de los personajes. Es importante destacar, sin embargo, que la elecci?n del personaje como categor?a principal de nuestro an?lisis no implica la exclusi?n de otros elementos de la narrativa. Detectamos que el personaje, elemento m?s actuante de la ficci?n, se encuentra radicalmente ensimismado en el texto hilstiano, y es acerca de este aspecto que pretendemos detenernos. Por lo tanto, investigaremos la relaci?n establecida entre la subjetividad exacerbada de los personajes y el lenguaje utilizado por la autora. Para eso, observaremos el recurso discursivo que es bastante recurrente en sus textos: el flujo de conciencia. Reflexionar acerca de este recurso es de fundamental importancia para nuestra investigaci?n, ya que la problematizaci?n del individuo, en la escrita de Hilst, pasa tambi?n por el desordenamiento del lenguaje. Es v?lido resaltar, todav?a, que consideraremos el contexto social en el cual la obra se inserta, promoviendo di?logos entre ambos con fin de evidenciar de qu? forma la sociedad se configura en la novela. En funci?n de esto, no entenderemos el aislamiento de los personajes solamente en su dimensi?n ontol?gica, pero tambi?n en su dimensi?n hist?rica y social.
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Liu, Xuejie. "Basic structure and formation mechanism of Ti-Si-N superhard nanocomposite coatings." Heimsheim : Jost-Jetter, 2009. http://d-nb.info/994974574/34.
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Liu, Xuejie. "Basic structure and formation mechanism of Ti-Si-N superhard nanocomposite coatings." Heimsheim Jost-Jetter, 2008. http://d-nb.info/99307751X/04.
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Almeida, Joel Alexandre Santiago. "Desenvolvimento de um cerâmico Al2O3/TI(C,N) para uso em maquinação." Master's thesis, Universidade de Aveiro, 2015. http://hdl.handle.net/10773/15707.
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Mestrado em Engenharia de MateriaisO principal objetivo deste trabalho é preparar um cermeto do tipo Al2O3/Ti(C,N) com propriedades mecânicas adequadas à sua utilização na maquinação de materiais do tipo DIN ISO 513:K01-K10 e ISO H01-H10. De forma a incrementar a sinterabilidade do cermeto investigou-se o efeito da adição de dopantes metálicos, nomeadamente alumínio metálico (Al) e hidreto de titânio (TiH2) e o efeito da substituição da moagem convencional por moagem de alta energia. As variáveis das etapas principais de processamento, i.e., da moagem, prensagem e sinterização, foram selecionadas com trabalho realizado quer na Universidade de Aveiro quer na empresa Palbit. Foram preparadas três composições do cermeto Al2O3/Ti(C,N) com adições de 5%TiH2, 1%Al e 5%TiH21%Al através da moagem de alta energia. Os parâmetros de moagem, i.e. a velocidade de rotação, o rácio bolas/pó e o tempo de moagem foram otimizados para os seguintes valores: 350 rpm, 10:1 e 5 h, respetivamente. A utilização da moagem de alta energia permitiu uma redução do tamanho de partícula dos pós até aproximadamente 100 nm e a obtenção de uma boa uniformidade da distribuição das fases (Al2O3+Ti(C,N)). A etapa de conformação foi efetuada por prensagem uniaxial seguida de prensagem isostática. A avaliação da reatividade dos cermetos através de dilatometria em atmosfera de vácuo revelou que a densificação é maioritariamente realizada em estado sólido. A adição de apenas 1%Al é a menos efetiva para a densificação. Os cermetos foram sinterizados através de sinterização convencional em forno de vazio a 1650ºC e prensagem a quente (1650ºC com uma pressão uniaxial de 25 MPa). Os valores de densificação obtidos, aproximadamente 80% e 100%, respetivamente, indicam que a aplicação de pressão durante a sinterização é efetiva para atingir densificações elevadas nos compactos, compatíveis com as suas aplicações tecnológicas. As propriedades mecânicas de dureza e de tenacidade avaliadas nos três cermetos apresentaram valores aproximados de 1800-1900 HV50 para a dureza e entre 5.4 e 7.7 MPa.m1/2 para a tenacidade à fratura.
The main goal of this work is to prepare a cermet type Al2O3/Ti(C, N) with mechanical properties adequate for use in machining type materials DIN ISO 513: K01-K10 and ISO H01-H10. In order to increase the sinterability of the cermet investigated the effect of addition of metal dopants, including metallic aluminum (Al) and titanium hydride (TiH2) and the effect of substitution of the conventional milling by high energy milling. The variables of the main processing steps, ie, milling, pressing and sintering were selected with work done both at the University of Aveiro either in Palbit company. It was prepared three cermet compositions Al2O3/Ti(C,N) with additions of 5%TiH2, 1%Al and 5%TiH21%Al by high energy milling. The grinding parameters, eg the rotational speed, the ratio balls / powder and the grinding time were optimized for the following values: 350 rpm, 10: 1 and 5 h, respectively. The use of high energy milling of the powders allowed a reduction of particle size to about 100 nm and to obtain a good uniformity of distribution of the phases (Al2O3+Ti (C,N)). The forming step was carried out by uniaxial pressing, followed by isostatic pressing. The evaluation of the reactivity of cermetos by dilatometry in a vacuum atmosphere revealed that the densification is performed mainly in a solid state. The addition of only 1% Al is less effective for densification. The cermets were sintered using conventional sintering in vacuum oven at 1650ºC and hot pressing (1650ºC with a uniaxial pressure of 25 MPa). The densification values, approximately 80% and 100%, respectively, indicate that the application of pressure during sintering is effective to achieve high densification in the compact, consistent with their technological applications. The mechanical properties of hardness and toughness evaluated in the three cermetos showed similar values of 1800-1900 HV50 for the hardness and between 5.4 and 7.7 MPa.m1/2 to the fracture toughness.
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Yoon, Su-Jong. "Synthesis and characterization of ceramics in the Ti-B-N-C system." Thesis, Brunel University, 1994. http://bura.brunel.ac.uk/handle/2438/5352.
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Titanium and boron nitride and carbide, titanium diboride were synthesized by carbothermic reduction as single phase as well as mixtures intended to form composite materials. The aim of the project is to study the physical chemistry of carbothermic reduction for the production of pure nonoxide ceramic powders and also for the in-situ formation of ceramic/ceramic partially-densified composites. The thermodynamic and kinetic factors that govern the phase constituents are discussed and the effect of processing parameters on the morphology and extent of reduction are also established. The first part of the present investigation is aimed at the production of titanium nitride, carbonitride and carbide powders and the in-situ formation of TiN/TiC partially-densified composites by the carbothermic reduction of titania in suitable nitriding atmospheres. The investigation includes the aspects of the thermodynamics and kinetics of the nitriding reaction and points out the reaction mechanism by identifying the phase formed after the nitridation process. The microstructures produced after the reduction-nitridation process have been correlated with the thermodynamic and kinetic parameters. The synthesized titanium nitride powder was identified as the carbonitride phase, Ti(CxN1_x), having a range of composition. The rate of reduction of TbO2 was found to be determined by the rate of oxygen diffusion in the sub-oxide lattice and the derived value of activation energy in the temperature range 1473K to 1773K from the Arrhenius plot is 120 kJ-mole-1 of T102. TI305 was found as a high temperature precursor phase for the formation of titanium nitride. The use of iron chloride as catalyst and activated charcoal in the mixtures of oxide increased the yield of titanium nitride phase by enhancing the rate of reduction of titanium oxides. The morphology of titanium carbonitride particles was dependent upon the reactivity of carbon and the temperature. The calculated equilibrium phase fields were found to be in agreement with the experimental data and provide a means to select the variables for the reduction condition for designing a required ceramic microstructure. The microstructure of boron nitrides is closely related to the structural chemistry of carbon and nitriding agent. The main aim of the second part of the project was to synthesize boron nitride and carbide powders and whiskers by carbothermic reduction of boric anhydride (6203) in nitrogen atmosphere and also to understand a relation between the processing parameters and the phases produced. The effect of processing conditions such as the gas composition, reactivity of carbon, reaction temperature and time as well as the composition of starting materials on the synthesis of boron nitride and carbide phases were studied. The reactivity of carbon, B/C ratio and gas composition were the most important variables that determined the formation, structure and morphology of the nitride. During the nitridation process, boron carbide phase also formed and played a significant role. The investigation also reports the evidence for the formation of metastable forms of BN i. e wurtzite and cubic BN. We also report the results of the solubility of nitrogen in C-saturated B4C structure. The third part of the present work is aimed at the production of TiB2 powders. Aspects of the formation of two or three ceramic phase mixtures were also examined together with the relative stability of the single phase mixed diborides with respect to pure diboride phase. The central aim of this part is to establish the mechanism of the synthesis reaction leading to the formation of uniform size of titanium diboride crystals. Titanium boride (TiB2) powder was produced in the powder form by the reduction of ingredient oxides with carbon via a gas-solid phase reaction. For the production of the composite microstructure, the nitrogen partial pressure was found to be the most critical factor. In the composite microstructure, the titanium nitride particles have a submicrometer size whereas the boride particle size is only a few micrometers with predominantly hexagonal morphology. Some calculated equilibrium phase fields have been experimentally verified. The empirical verification is a useful tool to establish the correctness of the calculated phase diagram. The theoretical approach therefore enables to identify the condition for the formation of phase mixtures. The constituent phases depend on the reduction conditions. For example, nitrides in equilibrium with Ti62 can only form above a critical nitrogen partial pressure whereas TiC or B4C form in the inert atmospheres. This result is applicable to all other ceramics. The investigation also shows the viability of production of the composite powder mixture via the oxide co-reduction technique. The synthesis of TIB2/TiN, TiB2ýC, TB2/TN/BN and mixed diboride composites is possible by employing the reduction route.
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Höglund, Carina. "Reactive Magnetron Sputter Deposition and Characterization of Thin Films from the Ti-Al-N and Sc-Al-N Systems." Licentiate thesis, Linköping University, Linköping University, Thin Film Physics, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-17683.
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This Thesis treats the growth and characterization of ternary transition metal nitride thin films. The aim is to probe deeper into the Ti-Al-N system and to explore the novel Sc-Al-N system. Thin films were epitaxially grown by reactive magnetron sputtering from elemental targets onto single-crystal substrates covered with a seed layer. Elastic recoil detection analysis and Rutherford backscattering spectroscopy were used for compositional analysis and depth profiling. Different x-ray diffraction techniques were employed, ex situ using Cu radiation and in situ during deposition using synchrotron radiation, to identify phases, to obtain information about texture, and to determine the thickness and roughness evolution of layers during and after growth. Transmission electron microscopy was used for overview and lattice imaging, and to obtain lattice structure information by electron diffraction. Film properties were determined using van der Pauw measurements of the electrical resistivity, and nanoindentation for the materials hardness and elastic modulus. The epitaxial Mn+1AXn phase Ti2AlN was synthesized by solid-state reaction during interdiffusion between sequentially deposited layers of (0001)-oriented AlN and Ti thin films. When annealing the sample, N and Al diffused into the Ti, forming Ti3AlN at 400 ºC and Ti2AlN at 500 ºC. The Ti2AlN formation temperature is 175 ºC lower than earlier reported results. Ti4AlN3 thin films were, however, not possible to synthesize when depositing films with a Ti:Al:N ratios of 4:1:3. Substrate temperatures at 600 ºC yielded an irregularly stacked Tin+1AlNn layered structure because of the low mobility of Al adatoms. An increased temperature led, however, to an Al deficiency due to an out diffusion of Al atoms, and formation of Ti2AlN phase and Ti1-xAlxN cubic solid solution. In the Sc-Al-N system the first ternary phase was discovered, namely the perovskite Sc3AlN, with a unit cell of 4.40 Å. Its existence was supported by ab initio calculations of the enthalpy showing that Sc3AlN is thermodynamically stable with respect to the binaries. Sc3AlN thin films were experimentally found to have a hardness of 14.2 GPa, an elastic modulus of 21 GPa, and a room temperature resistivity of 41.2 μΩcm.
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Eriksson, Anders. "Cathodic Arc Synthesis of Ti-Si-C-N Thin Films from Ternary Cathodes." Licentiate thesis, Linköpings universitet, Tunnfilmsfysik, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-61994.
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Cathodic arc deposition is a powerful technique for thin film synthesis, associated with explosive phase transformations resulting in an energetic and highly ionized plasma. This Thesis presents film growth through arc deposition from compound cathodes of Ti3SiC2, providing source material for plasma and films rich in Si and C. The interest for the resulting Ti-Si-C-N films is inspired by the two ternaries Ti-Si-N and Ti-C-N, both successfully applied as corrosion and wear resistant films, with a potential for synergistic effects in the quarternary system. When using a rotating substrate fixture setup, which is common in high capacity commercial deposition systems, the repeated passage though the plasma zone results in growth layers in the films. This effect has been observed in several coating systems, in deposition of various materials, but has not been explained in detail. The here investigated layers are characterized by a compositional modulation in Si and Ti content, which is attributed primarily to preferential resputtering in segments of rotation when the plasma has high incidence angle towards the substrate normal. For depositions in a non-reactive environment, the films consist of primarily understoichiometric TiCx, Ti, and silicide phases, and display a modest hardness (20-30 GPa) slightly improved by a decreasing layer thickness. Hence, the side effects of artificial layering from substrate rotation in deposition systems should be recognized. Adding N2 to the deposition process results in reactive growth of nitride material, formed in a wide range of compositions, and thereby enabling investigation of films in little explored parts of the Ti-Si-C-N system. The structure and properties of such films, comprising up to 12 at% Si and 16 at% C, is highly dependent on the supply of N2 during deposition. Superhard (45-50 GPa) cubic-phase (Ti,Si)(C,N) films with a nanocrystalline feathered structure is formed at N-content of 25-30 at%. At higher N2 deposition pressure, C and Si segregate to column and grain boundaries and the cubic phase assumes a more pronounced nitride character. This transformation is accompanied by substantially reduced film hardness to 20 GPa. Ti-Si-C-N films thus display a rich variety of structures with favorable mechanical properties, but in the regime of high Si and C content, the amount of N must be carefully controlled to avoid undesirable formation of weak grain boundary phases based on Si, C and N.
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Haag, Steffen. "Ionenstrahlgestützte Abscheidung dünner Funktionsschichtsysteme im System Ti-B-C-N und deren Charakterisierung." [S.l. : s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=968811477.
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Piallat, Fabien. "Plasma assisted chemical deposition (CVD/ALD) and integration of Ti(Al)N and Ta(Al)N for sub-20 nm metal gate." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENT015/document.
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L'intégration du métal dans les nœuds technologiques sub-20 nm requiert une conformité supérieure à celle permise par la PVD. Les techniques de CVD, plus spécifiquement la MOCVD et l'ALD, ont été identifiées comme les meilleures solutions pour le dépôt de métal. Pour une application de métal de grille, les alliages carbo-nitrurés de titane et tantale sont considérés comme les plus prometteurs. Dans ce travail une revue détaillée des mécanismes de dépôt par MOCVD et ALD, ainsi que sur l'influence du plasma sur les matériaux déposés est réalisée. Dans un premier temps, les fenêtres de procédés possibles pour un ajustement des propriétés des métaux sont inspectées attentivement. L'accent est mis sur l'impact du plasma sur le métal et sur les mécanismes réactionnels inhérents grâce à une caractérisation poussée du plasma. Par la suite, l'intégration de ces métaux est étudiée avec une analyse précise des interactions se déroulant aux interfaces. La corrélation entre les propriétés physico-chimiques et le comportement électrique des empilements métal/diélectrique à forte permittivité est soutenue par une analyse XPS. Finalement, le dopage aluminium de dépôts de TiN et TaN MOCVD est étudié pour l'obtention de grilles n-mos et p-mos. Par comparaison des propriétés et comportements du dopage aluminium de métaux déposés par PVD et MOCVD, des mécanismes de diffusion sont proposés afin d'expliquer le rôle de l'aluminium sur les variations observéesFor the sub-20 nm technological nodes metal conformity requirements are beyond the possibilities of the currently used PVD deposition technique. CVD techniques, more specifically MOCVD and ALD, are identified as the best techniques for metal deposition. For metal-gate application, titanium and tantalum carbo-nitrides alloys are considered as the most promising. In this work, a detailed review of MOCVD and ALD deposition mechanisms and plasma influence on the deposited material is carried out. First, process windows for successful tuning of the metal properties are examined. Plasma impact on the metal and the inherent reaction mechanisms are also highlighted with the help of plasma characterisation. Then great importance is given to the integration of these metals, by careful study of the interactions taking place at the interfaces. Correlations between physico-chemical properties and electrical behavior of the metal/high-k dielectric stack are introduced thanks to XPS characterisation. Finally, aluminium doping of MOCVD TiN and TaN is considered for n-mos and p-mos gate characteristics achievement. By comparison of the properties and behaviours of Al doped metals deposited by PVD and MOCVD, diffusion mechanisms are proposed to explain the role of Al in the observed changes
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Sanchette, Fredéric. "Synthèse et caractérisation de dépôts Al-Cr-(N) et Al-Ti-(N) obtenus par pulvérisation cathodique magnétron en condition réactive." Vandoeuvre-les-Nancy, INPL, 1996. http://www.theses.fr/1996INPL057N.
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Ce travail porte sur l'élaboration et la caractérisation chimique, structurale, mécanique et électrochimique de revêtements Al-Cr-(N) et Al-Ti-(N) obtenus par pulvérisation cathodique magnétron de cibles composites Al-Cr et Al-Ti dans des plasmas d'argon et d'argon/azote. Les mécanismes de transfert de matière sont d'abord étudiés avec l'aide de l'analyse métallurgique des revêtements, le diagnostic du plasma par spectrométrie d'émission optique et un modèle de pulvérisation adapté à la géométrie des cibles composites. Les revêtements bruts de pulvérisation sont composés de solutions solides microcristallines ou amorphes. L’azote favorise l'amorphisation des revêtements. Les solutions solides amorphes à base d'aluminium qui sont sursaturées en chrome ou en titane et, éventuellement, en azote sont particulièrement étudiées car elles offrent le meilleur compromis entre le renforcement mécanique des revêtements et leurs propriétés électrochimiques. La stabilité thermique de ces revêtements amorphes est aussi discutée
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Guevarra, Jonathan S. "Crystal structures of perovskite-related Can(Nb,Ti)nO3n+2 (n=5 and 6)." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=979215722.
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Schramm, Benítez Isabella Citlalli Verfasser], and Frank [Akademischer Betreuer] [Mücklich. "Defect-engineered (Ti,Al)N thin films / Isabella Citlalli Schramm Benítez ; Betreuer: Frank Mücklich." Saarbrücken : Saarländische Universitäts- und Landesbibliothek, 2017. http://d-nb.info/115209470X/34.
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Fenard, Emmanuelle. "Céramiques composites du système Ti/B/N : Propriétés mécaniques et résistance à la corrosion." Limoges, 2001. http://www.theses.fr/2001LIMO0029.
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Gilles, Sandra. "Elaboration de couches minces de (Ti,Al)N par OMCVD : étude thermodynamique et expérimentale." Grenoble INPG, 1997. http://www.theses.fr/1997INPG0155.
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Les couches minces de (ti, al)n font l'objet d'attentions particulieres a cause de l'amelioration significative de la resistance a l'oxydation qu'elles presentent par rapport aux revetements durs de tin. Nous avons teste l'utilisation de precurseurs organo-metalliques pour synthetiser des films de (ti, al)n a des temperatures inferieures a 400 c par la technique de depot chimique en phase vapeur omcvd. Les precurseurs choisis sont le tetradimethylamide de titane (tdmat), l'hexadimethylamide de dialuminium (hdmada) et le tri-isobutyl aluminium (tiba). Compte tenu des donnees thermodynamiques disponibles, nous avons pu, a l'aide d'un programme de simulations thermodynamiques, determiner certaines plages de parametres favorables au depot de phases pures de nitrures de titane - aluminium. Les diagrammes d'equilibre de phases stables et metastables du systeme ternaire ti-al-n ont ete etablis entre 200 et 1600 c. L'etude experimentale des depots des phases binaires tin et ain nous a permis d'optimiser les parametres et de voir leur influence sur la contamination des films. En fonction de ces resultats les depots de (ti,al)n ont ete realises a l'aide de deux melanges reactionnels : - tetradimethylamide de titane + hexadimethylamide de dialuminium + ammoniac - tetradimethylamide de titane + tri-isobutyl aluminium + ammoniac le premier melange reactionnel nous a permis de deposer a basse temperature (400 c) a une pression de 25 mbar, des films de (ti,al)n ; de structure cubique, ces films sont composes de grains de taille nanometrique. Le parametre le plus interessant pour faire varier le rapport al/ti est le debit d'ammoniac. Le deuxieme melange reactionnel semble pratique pour deposer des multicouches tin/aln.
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Forsén, Rikard. "Mechanical properties and thermal stability of reactive arc evaporated Ti-Cr-Al-N coatings." Licentiate thesis, Linköpings universitet, Nanostrukturerade material, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-79579.
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This licentiate thesis reports experimental and theoretical work on the high temperature mechanical properties and the thermal stability of cubic (c)-(Ti-Cr-Al)1-N1 coatings. It is demonstrated that it is possible to tailor and improve the properties of hard nitride coatings by different degrees of multicomponent alloying. When Cr is added to Ti-Al-N the coatings exhibit age hardening up to 1000 ºC which is higher compared to what is observed for Ti-Al-N. In addition, the coatings show a less pronounced hardness decrease when hexagonal (h)-Al-N is formed compared to Ti-Al-N. The improved thermal stability is discussed in terms of a lowered coherency stress and a lowered enthalpy of mixing due to the addition of Cr. When Ti is added to Cr-Al-N the formation and growth of the detrimental h-Al-N phase is suppressed and delayed improving the mechanical properties. This is discussed in terms of kinetic effects where the Ti atoms obstruct the Al diffusion and consequently the growth of h-Al-N precipitates. The microstructure evolution investigated at different stages of spinodal decomposition, coarsening and phase transformations are correlated to the thermal responses and the mechanical hardness of the coatings. Upon annealing up to 1400 ºC the coatings decompose into c-TiN, bcc-Cr and h-AlN. The decomposition takes place via several intermediate phases, c-CrAlN, c-TiCrN and hexagonal (β)-Cr2N. The oxidation resistance of (Tix-Cry-Al60)1-N1 is also investigated and presented for different x/y ratios. The results show that it is possible to generate coatings with both excellent mechanical properties and oxidation resistance improving the functionality in the working temperature range of 850-1100 ºC of for example cutting tools.
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Eriksson, Anders. "Cathodic Arc Synthesis of Ti-Si-C-N Thin Films : Plasma Analysis and Microstructure Formation." Doctoral thesis, Linköpings universitet, Tunnfilmsfysik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-86259.
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This Thesis explores the arc deposition process and films of Ti-Si-C-N, inspired by the two ternary systems Ti-Si-N and Ti-C-N, both successfully applied as corrosion and wear resistant films. The correlation between cathode, plasma, and film properties are studied for a comprehensive view on film formation. Novel approaches to adapt arc deposition to form multi-element films are investigated, concluding that the source of C is not a determining factor for film growth. Thus, cubic-phase films of similar properties can be synthesized from processes with either 1) ternary Ti-Si-C cathodes, including the Ti3SiC2 MAX phase, in N2 atmosphere or 2) Ti-Si cathodes in a mixture of N2 and CH4. With the Ti3SiC2 cathodes, superhard (45-50 GPa) cubic-phase (Ti,Si)(C,N) films can be deposited. The structure is nanocrystalline and feather-like, with high Si and C content of 12 and 16 at%, respectively. To isolate the effects of Si on film structure, magnetron sputtered Ti-Si-N films of comparatively low defect density was studied. These films show a strong preference for {200} growth orientation, and can be grown as a single phase solid solution on MgO(001) substrates up to ~9 at% Si, i.e. considerably higher than the ~5 at% Si above which a feather-like nanocrystalline structure forms in arc deposited films. On (011) and (111) growth surfaces, the films self-organize into TiN columns separated by segregated crystalline-to-amorphous SiNx. The conditions for film growth by arc were investigated through plasma studies, showing that plasma properties are dependent on cathode composition as well as phase structure. Plasma generation from Ti-Si cathodes, with up to 25 at% Si, show higher average ion charge states of Ti and Si compared to plasma from elemental cathodes, which may be related to TiSix phases of higher cohesive energies. The ion energy distributions range up to 200 eV. Furthermore, compositional discrepancies between plasma ions and film infer significant contributions to film growth from Si rich neutral species. This is further supported by depositions with a macroparticle filter, intended for growth of films with low surface roughness, where Si and C contents lower than the stoichiometry of Ti3SiC2 cathodes was measured in both plasma and films. Also the substrate geometry is critical for the film composition in plasma based film deposition, as evidenced by the formation of artificial layering from rotating substrate fixtures common in high capacity arc deposition systems. The layers are characterized by modulations in composition and crystallinity, primarily attributed to preferential resputtering in high ion incidence angle segments repeated through rotation.
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Anderbouhr, Stéphanie. "Dépôt chimique en phase vapeur de couches minces de (Ti,Al)N à composition variable." Grenoble INPG, 1999. http://www.theses.fr/1999INPG0061.
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Les couches minces de nitrures ont ete largement integrees dans differents secteurs industriels strategiques comme la microelectronique et le domaine de l'outillage mecanique. Dans ces domaines, le nitrure de titane reste un materiaux de choix. Toutefois, dans le domaine des revetements durs, de part sa faible resistance a l'oxydation, il est progressivement remplace par des nitrures ternaires tel le nitrure de titane-aluminium. Cette etude s'est portee sur l'elaboration de revetements durs de tin, aln, et essentiellement de (ti,al)n par deux procedes specifiques de depot cvd utilisant des chlorures gazeux generes par chloruration in situ d'une charge metallique : un procede basse pression active thermiquement (lpcvd) et un procede assiste par plasma (pacvd). L'optimisation des procedes a ete prealablement menee par un etude thermodynamique du systeme chimique ti-al-n-h-cl. Les diagrammes d'equilibre des phases stables et metastables du systeme ternaire ti-al-n ont ete etablis a differentes temperatures. Les equilibres obtenus sont pour la plupart en accord avec les resultats experimentaux. La mise au point des procedes d'elaboration et l'optimisation des conditions operatoires a ete effectuee dans le but de controler la composition des depots et d'obtenir in fine des revetements presentant les meilleures proprietes mecaniques et de resistance a l'oxydation a haute temperature (850\c). L'etude microstructurale des depots lpcvd et pacvd a montre que la phase deposee est la solution solide (ti,al)n de structure cfc avec presence d'une phase hexagonale aux plus fortes teneurs en al et que la limite de stabilite (cubique/hexagonale) du melange depend de la technique de depot adoptee. Des resultats probants en terme de resistance a l'oxydation et de resistance a l'usure et au frottement ont ete obtenus pour les depots de (ti,al)n a forte teneur en aluminium.
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Antunes, Vinícius Gabriel 1984. "Deposição e caracterização físico-química de filmes finos nanoestruturados (nanocompósitos) contendo Ti, C, N e O, Obtidos a partir de um precursor líquido (Ti(OC2H5)4)." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/276978.
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Orientador: Fernando AlvarezDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin
Made available in DSpace on 2018-08-24T22:24:16Z (GMT). No. of bitstreams: 1 Antunes_ViniciusGabriel_M.pdf: 3019304 bytes, checksum: 07f935b74d9527a192ce26b38e17afda (MD5) Previous issue date: 2014
Resumo: Os tratamentos de superfície a plasma são amplamente usados em diversas áreas de tecnologia, tais como: indústria metalmecânica, microeletrônica, plástico e medicina, para o crescimento de filmes finos, camadas protetoras em instrumentos e ferramentas de corte, funcionalização de superfícies plásticas, tecidos sintéticos, esterilização de instrumentos cirúrgicos e plasma reativo em semicondutores. Há alguns anos, uma nova família de filmes duros e protetores com baixo atrito compostos por nanoestrururas, tem sido intensamente pesquisada por apresentar propriedades particularmente interessantes, do ponto de vista da físico-química básica, como possíveis aplicações tecnológicas em que a demanda por desgaste, altas temperatura, e resistência mecânica são necessárias. A deposição de filmes finos, constituídos por nanocompósitos, e a compreensão de propriedades (mecânicas, elétricas, ópticas) desses novos materiais, gera um leque de possíveis aplicações tecnológicas. A partir de tais premissas, focalizamos o objetivo do trabalho em estudar a obtenção e caracterização das propriedades físico-químicas de filmes finos nanoestruturados (nanocompósitos), que contêm compostos de Ti, C, N, e O, utilizando a técnica de Deposição Química pela Decomposição do precursor líquido tetraetóxido de titânio (Ti(OC2H5)4) (PECVD, na sigla em inglês). Ressalta-se que o interesse em obter esses materiais, a partir do reagente em questão, reside no fato de que ele poderia substituir o uso de outros precursores de difícil manuseio, tais como o tetracloreto de titânio (TiCl4), o qual é normalmente utilizado em numerosas aplicações de deposições de filmes compósitos, mediante a técnica de PECVD, e cujo subproduto da reação gera reagentes altamente corrosivos. Em resumo, este trabalho contempla a caracterização da composição química, micro e nano estrutura de compósitos que contêm os compostos mencionados, em função das variáveis mais importantes de deposição. O presente estudo foi bem sucedido em obter nanocompósito e correlacionar a dependência das ligações químicas do material com os parâmetros mais importantes de deposição
Abstract: Plasma surface treatments are widely used in several technological areas (e.g., metallurgic industry, microelectronic, plastic industry, medicine) in order to obtain hard coatings on cutting tools and instruments, funtionalization of plastics and synthetic materials used in the textile industry, sterilization of chirurgic instruments, etching by reactive plasma in the semiconductor industry, etc. Recently, a new family of coatings deposited by plasma assisted techniques owing interesting physical chemical properties such as super-hardness, low friction and wear resistant, temperature and corrosion resistant, known as nano-composites, have been intensely studied.The objectives of this work is developing a nano composite containing Ti, C, N e O and understand as far as possible its physical and chemical properties. The material is obtained by plasma assisted enhanced chemical deposition (PECVD) using Titanium(IV) ethoxide ( (Ti(OC2H5)4) and N as precursors of the reaction. The importance of the attempt to use the cited precursor resides in the fact that it is a friendly liquid without corrosive o major toxic effects, as the normal precursors used in the actual industrial process (e.g., titanium tetrachloride, TiCl4). Summarizing, this work is focusing the research in the deposition and study of the physical and chemical properties of thin films nano composites obtained from Titanium(IV) ethoxide precursor. The study shows that the deposition procedure allows obtaining a material containing nanoscopics size crystallites of the compounds cited above. Finally, the relation of the material properties with the more important deposition parameters is discussed and presented
Mestrado
Física
Mestre em Física
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Liu, Xuejie [Verfasser]. "Basic structure and formation mechanism of Ti-Si-N superhard nanocomposite coatings / vorgelegt von Xuejie Liu." Heimsheim : Jost-Jetter, 2009. http://d-nb.info/994974574/34.
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Kussmaul, Armin. "Thermodynamische Berechnungen zum Einfluss reduzierender und oxidierender Atmosphären auf Werkstoffe im System Ti-Al-O-N /." Online version, 1998. http://bibpurl.oclc.org/web/37074.
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Godinho, Vanda. "Synthesis and characterization of magnetron sputtered thin films of the Ti-Al-Si-N(O) system." Doctoral thesis, Universite Libre de Bruxelles, 2011. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209969.
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The aim of this Thesis was on one side to contribute to a better understanding of the phases formed in the TiAlSiN(O) system and the influence of impurities on their properties. On the other side it was also aimed in the Thesis to individually study the phases forming the nanocomposite. In each chapter the individual conclusions from that particular chapter are presented, a summary of the most relevant conclusions and achievements is listed below.
¡à\
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished
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Eberling-Fux, Nicolas. "Matériaux composites à matrice nanostructurée dans les systèmes Si-B-C-Ti et Si-B-C-N." Bordeaux 1, 2006. http://www.theses.fr/2006BOR13235.
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Des matériaux composites à matrice céramique micro-nanostructurée et renfort fibreux en carbone ont été élaborés dans le système Si-B-C-X (X = Ti, N) par l'intermédiaire d'un nouveau procédé hybride alliant fiabilité, rapidité et minimisation des coûts. Ce dernier combine une étape d'imprégnation de préformes 3D (environ 2 mm d'épaisseur) à partir de suspensions de poudres céramiques nanométriques carbures et borures, suivie d'une étape de densification de la matrice pulvérulentes du composite. L'objectif repose sur la conception d'une matrice multiphasée amélirée présentant une ou des phases réfractaires, une phase borée assurant les mécanismes d'autocicatrisation dès 600°C et un phase déviatrice de fissures. Les applications envisagées sont aéronautiques pour un domaine de température de 600°C à 1100°C. Deux voies d'élaboration ont été explorées suivant la nature de la suspension initiale, à savoir des suspensions de poudres de carbure de silicium ou de carbure de titane dans lesquelles une poudre de carbure ou de nitrure de bore est ajoutée. Dans le cas de suspensions à base de poudres de SiC, le mélange de particules est dispersé dans un système suspensif à base d'éthanol et de polyéthylène imine. Les préformes avec ou sans interphase sont imprégnées à coeur de matériau et présentent des taux de remplissage compris entre 55 % et 70 % pour des temps d'exposition de 1 à 2 min. Ces dernières sont ensuite densifiées par frittage flash ou par infiltration réactive à partir de titane ou d'alliages fondus de manière à former respectivement des composites Cr / SiC - B4C ou SiC - BN, et des composites Cf / SiC(TIC) - TiB2 - Ti3SiC2. Le nitrure de bore et la phase ternaire Ti3SiC2 joue le rôle de fusible mécanique et d'interphase discrète au sein de la matrice composite. Dans le cas de suspensions à base de poudres de TiC, les particules sont préalablement soumises à un traitement acide en vue d'améliorer la dispersion du mélange de poudre dans le système éthanol + polyethylène imine. Présentant des taux d'imprégnation compris entre 50 % et 60 %, le matériau préimprégné est ensuite infiltré par du silicium ou un de ses alliages de manière à réaliser des composites à matrice SiC(TIC) - TiB2 - Ti3SiC2. L'ensemble des matériaux élaborés est caractérisé d'un point de vue morphologique, physico-chimique et mécanique. Des corrélations structure - propriétés sont établies.
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Pinot, Yoann. "Micro- et nanostructure des revêtements (Ti, Al)N et comportement tribologique au voisinage de la transition structurale." Thesis, Mulhouse, 2015. http://www.theses.fr/2015MULH0719/document.
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Les films de nitrures métalliques nanostructurés sont généralement utilisés comme revêtements protecteurs. Ti1-xAlxN (0 ≤ x ≤ 1) peut être considéré comme un système modèle, où TiN (cubique) et AIN (hexagonal) sont partiellement miscibles. L’élaboration par dépôt physique en phase vapeur donne au film une microstructure colonnaire complexe composée de phase métastable pouvant cohabiter avec des précipités localisés aux joints de grains. Une haute dureté et une grande résistance à l’oxydation sont observées pour un maximum d’atomes de Ti substitué par des atomes de Al en réseau cubique. Les conditions de dépôt et la composition jouent un rôle majeur sur la substitution des éléments métalliques (Ti ,Al). Nous avons préparé deux séries de films déposés par pulvérisation cathodique magnétron réactive à partir de cibles TiAl compartimentées et frittées. La micro- et nanostructure des films ont été analysées par Diffraction, Spectroscopie d’Absorption des rayons X et Microscopie Electronique à Transmission. L’usure des revêtements a été étudiée par microtribologie. Nous observons pour les films riches en Ti (x < 0,5) des directions de croissances [200]c et [111]c, caractéristiques d’un réseau cubique. Tandis que, les films riches en Al (x > 0,7) présentent une croissance de domaines bien cristallisés suivant la direction [002]h du réseau hexagonal. De plus, nous avons mis en évidence l’apparition de la transition cubique / hexagonal à des teneurs en Al plus élevée pour les films issus de cible frittée. Ces films montrent une meilleure résistance à la fissuration et à l’usure que ceux déposés à partir de cible compartimentéesTi1-xAlxN (0 ≤ x ≤ 1) is considered as a model system, where TiN (fcc) and AlN (hcp) do not mix over the whole composition range due to their low miscibility. However, the physical vapour deposition (PVD) allows achieving metastable phases of Ti1-xAlxN, where Al atoms are partially substituting for Ti in fcc lattice. Ti1-xAlxN coatings exhibit high hardness and oxidation resistance for the maximum Al substituted to Ti in fcc lattice (about x=0.6). The proportion of grain boundaries and the limit solubility play a major role on the mechanical properties and resistance to wear of the coatings. Several techniques are employed to investigate two sets of Ti1-xAlxN thin films deposited by magnetron reactive sputtering from two types of metallic targets onto Si (100). Lattice symmetry of crystallised domains and columnar growth structure of the films are characterized by X-ray diffraction (XRD) and electron microscopy (TEM, HRTEM). Several local probes such as X-ray absorption fine structure (XAFS), diffraction anomalous fine structure (DAFS) and Electron Energy Loss Spectroscopies (EELS) which are very sensitive to the symmetry of the atomic sites either octahedral for fcc lattice or tetrahedral for hcp one are carried out. For Ti-rich films (x < 0.5), the competitive growth of cubic domains between [200]c and [111]c is observed. For Al-rich films (x > 0.7) have a domain growth well crystallized in the direction [002]h the hexagonal lattice. In addition, the cubic / hexagonal transition in Al contents higher is observed for films from sintered target. These films show better wear resistance than those deposited from target compartmentalized
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Munardi, Adriantono. "Polymérisation de l'acétylène par un nouveau système d'amorçage n-BuLi/Ti (OnBu)4, étude cinétique, structurale et morphologique." Grenoble : ANRT, 1985. http://catalogue.bnf.fr/ark:/12148/cb37594996c.
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TASAYCO, CARLOS MANUEL SANCHEZ. "STRUCTURAL, MECHANICAL AND TRIBOLOGICAL PROPERTIES OF TIB2 AND TI-B-N FILMS DEPOSITED BY REACTIVE DC MAGNETRON SPUTTERING." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2007. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=10020@1.
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COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIORCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
O presente trabalho teve como objetivo central o estudo das modificações nas propriedades estruturais, mecânicas e tribológicas causadas pela incorporação de nitrogênio em filmes de diborato de titânio (TiB2) crescidos pela técnica de erosão catódica assistida por um campo magnético. Os revestimentos de Ti-B-N com diferentes conteúdos de nitrogênio foram depositados em substratos de silício cristalino (100) a partir da erosão de um alvo de diborato de titânio mediante o uso da técnica de erosão catódica em uma atmosfera de argônio e nitrogênio e com tensões de polarização variando entre +100V e - 100V. Os efeitos do conteúdo de nitrogênio e a influência da tensão de polarização na estrutura e no comportamento tribológico foram investigados com o uso da técnica nuclear de retroespalhamento Rutherford (RBS), espectroscopia de fotoelétrons induzida por raios-x (XPS), difração por raios-x (XRD), perfilometria (medidas de tensão interna), microscopia de força atômica (AFM) e de ângulo de contato. Os resultados do presente trabalho mostraram que a incorporação de nitrogênio produz filmes com tensões internas cada vez mais compressivas. No entanto a mudança da tensão de autopolarização a valores positivos provocou uma relaxação na tensão interna. Nesses casos, foi observada uma melhor adesão dos filmes aos substratos de silício. Os resultados de XPS mostraram que as fases, TiB2, BN e TiN, estão presentes nos filmes de Ti-B-N e a caracterização por XRD determinou a estrutura nanocristalina desses revestimentos. Medidas de AFM indicaram valores de rugosidade superficial entre 1 e 2nm.
The main purpose of the present work was the study of the effects on the structural, mechanical and tribological properties of the incorporation of nitrogen in titanium diboride films (TiB2) grown by reactive dc magnetron sputtering. Ti-BN coatings with different N contents were deposited on Si (100) substrates from a TiB2 target. The sputtering was carried out in an Ar-N2 gas mixture with a substrate bias voltage in the range between +100V e -100V. The effects of the nitrogen content and the influence of substrate bias voltage on the coatings properties were studied by Rutherford Backscattering Spectrometry (RBS), XRay photoelectron spectroscopy (XPS), X-Ray diffraction (XRD), profilometry (internal stress measurements), atomic force microscopy (AFM) and contact angle measurements. The results of the present work show that nitrogen incorporation produces films with higher compressive internal stress. However, a positive substrate bias reduces the compressive stress, thus resulting in a better adhesion to the substrate. The XPS results showed that the TiB2, TiN and BN phases are present in the Ti-B-N films. Characterization by XRD determined the nanocrystalline structure of Ti-B-N coatings. Measurements by AFM revealed low surface roughness values.
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Dutron, Anne-Marie. "Dépots LPCVD de siliciures ternaires Me-Si-N (Me= Re, W, Ti, Ta) pour des applications en microélectronique." Grenoble INPG, 1996. http://www.theses.fr/1996INPG0092.
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Dans la metallisation avancee des circuits integres, le cuivre est envisage comme futur metal d'interconnexion et de contact. Cependant, son utilisation reste conditionnee par l'usage d'une barriere de diffusion tres performante susceptible de bloquer sa migration lors de traitements thermiques dans les materiaux voisins constitutifs des circuits integres. Cette etude a concerne l'elaboration par lpcvd de siliciures ternaires de type me-si-n (me= re, w, ti, ta) sur substrat de sio#2, et plus particulierement elle s'est orientee vers le choix d'une barriere de diffusion adequate repondant aux criteres requis pour une possible application industrielle. Une etude thermodynamique au prealable a notamment permis de classer les quatre materiaux en differentes categories. L'etude experimentale a montre que les systemes a base de metaux depourvus de nitrures men (cas du rhenium) ou depourvus de nitrures men stables (cas du tungstene) etaient obtenus a l'etat amorphe ou nanocristallise. En revanche les materiaux tisin et tasin dont les nitrures metalliques sont stables ont ete deposes a l'etat cristallise. Les caracterisations physico-chimiques des films ternaires ont ete realisees par diffraction rx, rutherford backscattering spectrometry, microscopies electroniques a balayage et a transmission, resistivite electrique, spectrometrie photoelectronique. Nous avons montre que le procede lpcvd utilise permettait un excellent recouvrement des marches et semblait donc plus interessant qu'un procede pvd. Les performances des quatre systemes me-si-n (me= re, w, ti, ta) en presence de cuivre et sous traitements thermiques ont ete evaluees de maniere exploratoire par analyse auger ainsi que par une caracterisation electrique c (v). Les proprietes du materiau ternaire wsin, en particulier sa morphologie amorphe, sa faible temperature de depot, sa resistivite electrique voisine de 1milliohm. Cm et ses performances, correspondent aux principaux criteres de selection d'une barriere de diffusion adequate
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Le, Brizoual Laurent. "Analyse expérimentale et modélisation du dépôt de films de Ti-Si-N par pulvérisation réactive r. F. Magnétron." Nantes, 2000. http://www.theses.fr/2000NANT2125.
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Cette thèse a pour thème l'étude expérimentale et la modélisation du dépôt de films minces de Ti-Si-N par pulvérisation réactive r. F. Magnétron. Ces couches minces sont élaborées par pulvérisation d'une cible de Ti5Si3 dans un mélange réactif argon/azote. L'objectif de cette étude est de caractériser à la fois le plasma, la pulvérisation et les films minces afin de déterminer l'influence de la puissance rf et du pourcentage d'azote dans le mélange sur la structure et les propriétés des films de Ti-Si-N. Enfin, on étudie les propriétés de barrière à la diffusion du cuivre de ces films minces de Ti-Si-N pour des applications microélectronique.
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Ngendahimana, Aimable. "Investigation of Novel Routes in the Synthesis of TiNF and Compounds in the Ti-N-O-F System." Youngstown State University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1278100734.
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Hong, Kai Cheng, and 洪愷誠. "Study of Ti-Si-N film." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/60285077502466019287.
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Chen, Jun-Hao, and 陳君濠. "Deposition and characterization of Ti-Si-N, Ti-Si-C-N films by cathodic arc plasma evaporation." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/zrzu7r.
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碩士國立虎尾科技大學
材料科學與綠色能源工程研究所
97
There are two phases in this study. In phase one, nanocomposite Ti-Si-N films were deposited by a filtered cathodic arc plasma deposition system. The influences of bias voltages on the microstructure, mechanical and corrosion properties of the films were investigated. In phase two, Ti-Si-N and Ti-Si-C-N films were deposited by a dual cathodic arc plasma deposition system. The influences of C2H2/N2 flow rate ratio on the microstructure, mechanical properties, corrosion resistance and oxidation behavior of the films were investigated. Field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), X-ray diffraction techniques (XRD), X-ray photoelectron spectroscope (XPS), Raman spectroscopy, nano-indenter, wear and corrosion testes were also employed to investigate the microstructures and properties of films. The results of the experiment show that Ti-Si-N films which were deposited using filter system revealed characteristics which are smooth surface, dense structure, good wear and corrosion resistance. The incorporation of C in Ti-Si-N film improves the wear behavior of the films while that were unbeneficial for corrosion and oxidation resistance. The friction coefficients of the TiSiCN films were between 0.2 and 0.3. The hardness of the film decreased when the C2H2/N2 flow rate ratio increased, the value of the hardness were between 4GPa~34GPa. After oxidation at high temperature, the oxide layer consists of TiO2 and SiO2 which presented as a solid solution. As the C content increased, the dominant TiO2 phase in oxide layer changed from rutile to anatase.
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Dashdorj, Dugersuren. "Spin distribution in preequilibrium reactions for ⁴⁸Ti + n." 2005. http://www.lib.ncsu.edu/theses/available/etd-03252005-191446/unrestricted/etd.pdf.
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Bangani, Vuyokazi Lusanda. "Computation of some properties of Ti-Si-C and Ti-Al-N MAX phase materials." Thesis, 2010. http://hdl.handle.net/10539/8346.
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The "MAX" phases are a class of ductile nanolaminated ternary nitrides and car-
bides, including about 60 known phases. The chemical formula for the MAX phase is
Mn+1AXn where M is an early transition metal. They consists of the 211, 321 and
412 groups. There are over 40 M2AX phases in existence.The M2AC MAX phase
category is divided into two subgroups, the V(B) and VI(B) transition metals. There
are three M3AX2 (Ti3SiC2, Ti3GeC2 and Ti3AlC2) and one M4AX3 (Ti4AlN3): As
for the 321 MAX- phases the chemical formula can be written as Ti3AC2, where A =
Al, Si, Ge. This group comprises of (Ti3SiC2, Ti3GeC2 and Ti3AlC2). MAX phase
properties are of more than two elements. They can be "sliced or diced" using a man-
ual hacksaw. These materials are used in applications such as industrial robots, disc
drives, electronics and MEMS devices.
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Buchholz, Stephen. "RECIPROCATING WEAR RESPONSE OF Ti(C,N)-Ni3Al CERMETS." 2011. http://hdl.handle.net/10222/14409.
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Titanium carbonitride (Ti(C,N)) cermets have become more popular in recent research
due to their mix of high hardness, high hot hardness, good ductility, chemical stability,
and low densities. These mechanical properties make Ti(C,N)-cermets especially
desirable as a replacement for current ‘hardmetals’, such as tungsten carbide cobalt (WCCo),
as it is known that WC-Co exhibits poor mechanical behaviour at elevated
temperatures. Additional interest and research has been conducted in reference to binders
which enhance the cermet’s capability to retain strength at high temperatures while
remaining ductile. One such binder, Ni3Al actually increases in yield strength up to a
temperature of ~900°C. In this thesis, the production method utilizing melt infiltration for
TiC, Ti(C0.7,N0.3), Ti(C0.5,N0.5), and Ti(C0.3,N0.7)-based cermets with Ni3Al binder
contents of 20, 30 and 40 vol. % have successfully been developed and utilized. This
process produced high density samples at each nitrogen content for all binder contents,
excluding Ti(C0.3,N0.7). Ti(C0.3,N0.7)-Ni3Al samples at 20 and 30 vol. % suffered from
poor infiltration and could not be tested. The reciprocating wear mechanisms were
examined, using a ball-on-flat test, utilizing WC-Co spheres with a diameter of 6.35 mm
as a counter-face, and test parameters of 20 Hz, 2 hrs., and applied loads of 20, 40, 60 and
80 N. The wear tracks were examined using optical profilometry, SEM, and EDS to
determine the volumetric wear rate, and the dominant wear mechanisms. The wear
volume, and wear mechanisms were compared with the effect of binder content, nitrogen
content, and applied load.
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Holmes, Melanie. "Electrochemical Behaviour of Ti(C,N) and TiC Cermets." 2012. http://hdl.handle.net/10222/15345.
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Three samples of Ti(C,N) were fabricated with 40 vol.% Ni3Al: Ti(C0.3N07), Ti(C0.5N0.5) and Ti(C0.7N0.3), as well as TiC with 10, 20, 30 and 40 vol.% Ni3Al binder addition by means of melt infiltration and sintering. Each sample was evaluated for density and microstructure before being placed in a flat cell for electrochemical testing. Open circuit potential was evaluated, followed by the application of a cathodic potential, whereby the response was tracked using Corrware corrosion software throughout the duration of potentiodynamic testing. Following corrosion testing, each sample was reevaluated for changes in microstructure and chemical composition. Ti(C,N) samples were found to have adequate resistance to corrosion, with increased resistance with increasing carbon content, however these samples demonstrated a greater frequency of breakdown and repassivation, suggesting a greater susceptibility to corrosion, despite the initial improved resistance. SEM imaging demonstrated significant crevice corrosion throughout. TiC-cermets demonstrated similar results in terms of SEM evaluation of microstructure. TiC-cermets with the lowest binder content (10 vol.% Ni3Al) demonstrated greater initial resistance to corrosion but also had the greatest potential for breakdown.
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Naidoo, Melisha. "Preparation of (Ti,Ta)(C,N) by mechanical alloying." Thesis, 2013. http://hdl.handle.net/10539/12352.
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The research described in this dissertation concerns an investigation into the development of new/modified Ti(C,N)-based cermet materials for applications relating to the metal machining industry.
Ti(C,N)-based cermets are widely employed for high speed machining owing to their attractive properties such as high hot hardness, chemical stability and excellent wear resistance. However, the increasing demand for high performance, advanced materials has steered research towards the development of novel tooling materials using unconventional processing methodologies. The mechanical alloying technique has shown promising results in this regard. The technique has been identified as a powerful tool for the development of advanced engineering materials including equilibrium, non-equilibrium and composite materials. By understanding the composition-microstructure-property relationship, guidelines can be provided with regard to producing materials possessing desirable mechanical properties. As such, the synthesis of the (Ti,Ta)-carbonitride solid solution was investigated by mechanically alloying brittle-ductile and brittle-brittle components.
When brittle-ductile Ti(C,N) and Ta powders were mechanically alloyed, the (Ti,Ta)-carbonitride solid solution was successfully obtained. Mechanical alloying greatly improved the sinterability of the Ti(C,N)-Ta powders and full densification was obtained in solid state. As a result of high energy milling, nanocrystalline Ti(C,N) was obtained. Consequently, cermets produced with these mechanically alloyed powders showed a fine microstructure and possessed superior mechanical properties, as compared to conventional ball milled sintered cermets.
Conversely, formation of the (Ti,Ta)(C,N) solid solution phase was unsuccessful by the mechanical alloying of brittle-brittle Ti(C,N) and TaC powders. Owing to the brittleness of the powders and the low diffusion coefficients in the carbide lattices, the mechanical alloying process served only to refine the grain size of the Ti(C,N) and TaC phases, whilst both phases remained unreacted by the end of milling. Consequently, only partial dissolution was achieved during sintering of the mechanically alloyed Ti(C,N)-TaC powders. As such, poor densification was obtained in these samples which served to lower their mechanical properties.
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Lee, Chien-Chih, and 李建志. "Study on Characteristics of (Ti,TiAl)N/(Ti,TiAl)CN Mixed Coatings by Filtered CAD Process." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/44217153013193875027.
Full textAbstract:
碩士大同大學
材料工程學系(所)
94
The work investigated to improve the defect of the bigger particle by Cathodic Arc Deposition (CAD) system with filtered. Because the TiN、TiAlN and TiCN coatings are popularly investigated before. Thereby, in this case, use a Ti target and TiAl target moreover N2 and C2H2 gases are through into with the process parameters to deposited (Ti,TiAl)N and (Ti,TiAl)CN two mixed films. They expect to obtain excellent properties besides to compare with filtered effect. Via knew with the experiment, the filter improves the defect of bigger particle, there are best improvement in roughness (Ra)、adhesion and porosity, moreover the structure cannot change. Also because the porosity decrease to improved with the corrosion resistance. But the particle decrease resulted in the decrease of depositing rate.
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Wang, Jyh-Liang, and 王志良. "Characterization of Sputtered TiB2 and Ti-B-N Diffusion Barriers." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/20441733527437218707.
Full textAbstract:
碩士國立成功大學
材料科學及工程學系
87
TiB2 and Ti-B-N films deposited by co-sputtering from a TiB2 and a boron target are evaluated as diffusion barriers for Cu/
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Figueiredo, José Miguel Fernandes. "Analysis of the tribological behaviour of W-Ti-N coatings." Master's thesis, 2013. http://hdl.handle.net/10316/23872.
Full textAbstract:
The aim objective of this work is to provide an experimental database for the tribological characteristics, at room and warm temperature (100ºC, 150ºC and 200ºC), between the AA5754-O aluminium alloy and a steel (H13) coated with a thin film (W-Ti-N). The experimental database was built based on pin-on-disk tests, without lubricant and using a minimum amount of lubricant. In order to reproduce the different contact conditions associated to sheet metal forming process, two types of steel samples were coated: planar and spherical. The first type of samples was tested using as counter-body aluminium pins. The second type of samples was the counter-body of the tests performed with aluminium sheets.
The pin-on-disk tests were performed under identical conditions for: (i) planar sample coatings, obtained with different deposition conditions, tested at room temperature with the goal of analysing the influence of the coating properties in the contact conditions; (ii) aluminium sheets, using coated balls corresponding to one of the deposition conditions (N9). A different amount of lubricant was applied for each aluminium sheet, with the main goal of analysing the influence of the lubricant amount in the contact conditions, including the temperature effect; (iii) planar sample coatings (N9) using different amounts of lubricant, in order to evaluate the influence of the lubricant amount in the contact conditions, including the temperature effect.
The analysis of the minimum, maximum and average friction coefficients determined for each test, allowed to draw some global conclusions. The coated samples that present the lower range for the friction coefficient are not necessarily the ones with the lower wear volume for the pin. For the tests performed with aluminium sheets against coated and steel balls, it was observed a different evolution of the friction coefficient with time, associated to the temperature increase, as a result of the alteration of the lubricant characteristics. This effect was not observed for the tests performed with coated samples against the aluminium pins, which can be related with the different sample roughness. Globally, the average friction coefficient increases with temperature in case of the sheet planar sample, while it was not possible to determine the influence of the lubricant amount for the coated planar samples, since the average friction coefficient is similar for both samples, for each temperature.
This work also constitutes an important database for allowing the improving of the experimental procedure, results analysis and test planning in future works. In this context, some recommendations were listed for future reference.
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Lin, Nai-Yuan, and 林乃元. "Mechanical Properties and Oxidation Resistance of Ti–Si–N Coatings." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/5h49f3.
Full textAbstract:
碩士國立臺灣海洋大學
材料工程研究所
106
Ti–Si–N coatings were fabricated using reactive direct current magnetron cosputtering. Fixed titanium target power and changes silicon power. The Ti–Si–N coatings with Si contents of 3–16 at. % exhibited crystalline, whereas the Ti–Si–N coatings with Si contents of 20 and 23 at. % were near-amorphous. The Ti31Si16N53 coatings exhibited maximum mechanical property levels, including a nanoindentation hardness of 19.2 GPa and a Young’s modulus of 247 GPa. The oxidation resistance of the Ti–Si–N coatings was evaluated through annealing at 600 ℃ in a 1%O2–99%Ar atmosphere. The Ti–Si–N coatings showed good oxidation resistance. High silicon content coatings. Rutile TiO2 formed in the early stage of oxidation, however, the reflection intensity of X-ray diffraction decreased in further annealing. To explore the stability in glass molding procrsses, thermal cycles annealing, involving annealing at 270 ℃ to 600 ℃ and maintaining at 600 ℃ ± 10 ℃ hold for 1 min. The coatings withstands continuous temperature changes over 500 cycles. In this study, transmission electron microscopy and X-ray photoelectron spectroscopy were applied to investigate the evolution of nanostructure and bonding characteristics of the annealed Ti–Si–N coatings. Keywords: Annealing, Mechanical properties, Oxidation, Transmission electron microscopy; X-ray photoelectron spectroscopy