Journal articles: 'Powder metal explosive property'

1

Tomoshige, Ryuichi, Seiichiro Ii, Masahiro Fujita, and Akira Chiba. "Hot Dynamic Densification of Materials by Utilizing Underwater Shock Wave." Materials Science Forum 706-709 (January 2012): 793–98. http://dx.doi.org/10.4028/www.scientific.net/msf.706-709.793.

Full text

Abstract:

Hot dynamic densification method was developed by combining self-propagating high temperature synthesis (SHS) with explosively shock powder compaction technique. This method is extremely short time processing. The main purpose in this study is to perform from synthesis to densification of TiB2-TiN system high temperature ceramic composites and TiB2-TiNi-Cu system functionally graded materials (FGMs) in one step. In TiN-TiB2 ceramic composites, they showed up to 95% of relative density. It was appeared by TEM observations that both the two phases joined tightly each other. The FGMs also were produced by the same technique. They indicated no interlayer exfoliation and no macro cracks after thermal shock tests from 973 K to room temperature. It was shown that thermoelastic property of intermetallic TiNi phase as intermediate layer between ceramics and metal layers operated effectively.

APA, Harvard, Vancouver, ISO, and other styles

2

Mohammadi, K., and A. Dravizeh. "Explosive Compaction of Metal Powder." Advanced Materials Research 83-86 (December 2009): 959–67. http://dx.doi.org/10.4028/www.scientific.net/amr.83-86.959.

Full text

Abstract:

In the present study ,the shock wave consolidation technique was used to produce bulk samples from metal powders .To method of consolidation were used to produce bulk samples, single consolidation and Two-Coaxial consolidation .after explosion ,the container tubes were cut and density of bulk , ratio of RDX to mass of flying tube (R) ,ratio of RDX to mass of powder(K),detonation velocity ,detonation pressure ,kinetic energy of flyer tubes and plastic work were calculated for all tests and finally cross section of samples were observed by SEM. The results show modified situation for Two-Coaxial consolidation by comparison in single tube consolidation.

APA, Harvard, Vancouver, ISO, and other styles

3

Shavelkina, Marina B., Ravil Kh Amirov, Tatyana I. Borodina, Viktor I. Kiselev, Tatiana B. Shatalova, and Kamille S. Rabadanov. "FORMATION OF NANO STRUCTURES IN RESULT OF HOMOGENOUS NUCLEATION OF CARBON OBTAINED IN THERMAL PLASMA UNDER ATMOSPHERIC PRESSURE." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 59, no. 8 (2018): 27. http://dx.doi.org/10.6060/tcct.20165908.34y.

Full text

Abstract:

Thermal plasma processing of carbon sources using a plasma jet with high heat capacity is one of the most promising methods for the synthesis of new materials. This paper describes the low-temperature deposition of carbon nanomaterials by remote plasma-enhanced chemical vapor deposition (PECVD) in the absence of catalysts. The remote PECVD process differs from conventional and direct PECVD process in two ways: (a) only a subset of the process reactants and/or diluents are directly plasma excited; and (b) thin film deposition takes place on a substrate that is outside of the plasma glow region. In conventional CVD methods, carbon is produced from the decomposition of carbon sources such as hydrocarbons, carbon monoxide, alcohols, and so on, over a metal catalyst. The unavoidable metal species remaining in carbon nanomaterials would lead to obvious disadvantages for property characterization and application exploration. Despite sustained efforts, it is still an intractable problem to remove metal catalysts completely from carbon nanomaterials samples without introducing defects and contaminations. Good reactor design allowed to overcome problems of chemical and structural purity, and poor process robustness in terms of phase composition of product from run to run. For the synthesis of graphene materials, carbon black, carbon nanotubes, nanowires we used the thermal plasma generator which is a high current divergent anode-channel DC plasma torch. The experiment involved a simultaneous input of hydrocarbons (methane, propane, butane, acetylene) with the plasma forming gas (helium, argon, nitrogen) into the plasma torch, wherein heating and decompositions occurred in the plasma jet and in the region of the arc discharge, followed by condensation of the synthesis product on metallic surfaces. The deposition rate was varied with distance from the plasma. Consumption of carbon source, plasma forming gas and plasma torch power were changed independently from each other. For the experimental conditions the electric power of plasma torch was set up to 40 kW. Regularities of formation of carbon thread-like nanostructures and graphene in the course of hydrocarbons pyrolysis in thermal plasma without participation of catalytic particles were studied by means of electron microscopy, X-ray diffraction, IR-spectrometry and thermogravimetry. Depending on the pyrolytic synthesis parameters, different proportions of crystal carbon and soot may be obtained. It has been demonstrated that the phase composition is varied by hydrocarbons flow rate, plasma forming gas pressure and dc plasma torch power. It has been established through the experiments that carbon nucleation is volumetric and proceeds according to the model of explosive soot formation.

APA, Harvard, Vancouver, ISO, and other styles

4

Krokhalev, A. V., V. O. Kharlamov, M. A. Tupitsyn, E. A. Kosova, S. V. Kuzmin, and V. I. Lysak. "RESEARCH OF THE MECHANISM OF SEALING POWDER MIXTURES BASED ON SILICON CARBIDE IN EXPLOSIVE PRESSING." IZVESTIA VOLGOGRAD STATE TECHNICAL UNIVERSITY, no. 7(242) (July 29, 2020): 20–24. http://dx.doi.org/10.35211/1990-5297-2020-7-240-20-24.

Full text

Abstract:

The effects of the metal binder content and parameters of shock-wave compression on the compaction of SiC-Ti powder mixtures under explosive loading were investigated; microstructure of the obtained materials; The prevailing mechanisms of compaction of powder mixtures of silicon carbide with titanium during explosive pressing are revealed.

APA, Harvard, Vancouver, ISO, and other styles

5

Xu, Jie, and Kou-Lin Zhang. "Preparation, characterization and luminescence-sensing properties of two ZnII MOFs with mixed 5-amino-2,4,6-tribromoisophthalic acid and bipyridyl-type ligands." Acta Crystallographica Section C Structural Chemistry 75, no. 7 (2019): 859–71. http://dx.doi.org/10.1107/s2053229619007435.

Full text

Abstract:

The bromo-substituted aromatic dicarboxylic acid 5-amino-2,4,6-tribromoisophthalic acid (H2ATBIP), in the presence of the N-donor flexible bipyridyl-type ligands 1,3-bis(pyridin-4-yl)propane (bpp) and N,N′-bis(pyridin-4-ylmethyl)oxalamide (4-bpme) and ZnII ions, was used as an O-donor ligand to assemble two novel luminescent metal–organic frameworks (MOFs), namely poly[[(μ-5-amino-2,4,6-tribromoisophthalato-κ2 O 1:O 3)[μ-1,3-bis(pyridin-4-yl)propane-κ2 N:N′]zinc(II)] dimethylformamide monosolvate], {[Zn(C8H2Br3NO4)(C13H14N2)]·C3H7NO} n , (1), and poly[[(μ-5-amino-2,4,6-tribromoisophthalato-κ2 O 1:O 3)diaqua[μ-N,N′-bis(pyridin-4-ylmethyl)oxalamide-κ2 N:N′]zinc(II)] monohydrate], {[Zn(C8H2Br3NO4)(C14H14N4O2)(H2O)2]·H2O} n , (2), using the solution evaporation method. Both (1) and (2) were characterized by FT–IR spectroscopy, elemental analysis (EA), solid-state diffuse-reflectance UV–Vis spectroscopy, and powder and single-crystal X-ray diffraction analysis. Complex (1) shows a two-dimensional (2D) corrugated layer simplified as a 2D (4,4) topological network. The supramolecular interactions (π–π stacking, hydrogen bonding and C—Br...Br halogen bonding) play significant roles in the formation of an extended three-dimensional (3D) supramolecular network of (1). Complex (2) crystallizes in the chiral space group P212121 and exhibits a novel 3D homochiral framework, showing a diamond-like topology with Schläfli symbol 66. The homochirality of (2) is further confirmed by the solid-state circular dichroism (CD) spectrum. The second harmonic generation (SHG) property of (2) was also investigated. The hydrogen and C—Br...Br/O halogen bonding further stabilize the framework of (2). The central ZnII ions in (1) and (2) show tetrahedral and octahedral coordination geometries, respectively. The coordinated and uncoordinated water molecules in (2) could be removed selectively upon heating. Most importantly, (1) and (2) show rapid and highly sensitive sensing for a large pool of nitroaromatic explosives (NAEs).

APA, Harvard, Vancouver, ISO, and other styles

6

Yakovleva, S. P., S. N. Makharova, and M. I. Vasilyeva. "Technology of Production of Diamond-Abrasive Composites with Metal Matrix." Materials Science Forum 992 (May 2020): 296–300. http://dx.doi.org/10.4028/www.scientific.net/msf.992.296.

Full text

Abstract:

The prospects of using the method of explosive pressing for solving urgent problems of creating high-performance diamond composites for instrumental purposes on binders of powders of fairly cheap materials are substantiated. Purpose of this work is to develop the technology of diamond-abrasive composites synthesis from powders mixtures of natural diamond and widespread low-cost iron-carbon alloys which combines explosive pressing and subsequent short-term high-temperature heating. The processes of varying the compositions of diamond-metal powder mixtures, the parameters of their explosive pressing and the modes of subsequent heat treatment of the resulting compacts are studied. It is shown that the use of explosion energy at the stage of powder briquetting opens up new opportunities for the production of high-performance diamond-containing materials with a matrix of iron-carbon alloy powders. This is due to the specifics of the explosive action which results in the activation of the bonding material which becomes obvious with further high-temperature heating in its intensive hardening and acceleration of diffusion processes. It is revealed that the shock waves create thermobaric conditions that allow for better preservation of the diamond component than with traditional methods of sintering. Samples of abrasive diamond composites with wear resistance corresponding to the level of wear resistance of industrial diamond dressers but with half the consumption of diamond raw materials were obtained.

APA, Harvard, Vancouver, ISO, and other styles

7

Murr, L. E., M. Pradhan, U. Sudarsan, and C. S. Niou. "Electron microscopy of explosively fabricated copper oxide superconductors." Proceedings, annual meeting, Electron Microscopy Society of America 47 (August 6, 1989): 190–91. http://dx.doi.org/10.1017/s0424820100152926.

Full text

Abstract:

Efforts to fabricate useful devices or fixtures from copper oxide superconductor powders, especially YBa2Cu3O7, have been somewhat critically dependent upon structural and microstructural information provided by electron microscopy (especially SEM and TEM). In our own research, which involves the fabrication of monolithic structures encapsulating copper oxide superconducting, powdered material within a metal matrix such as copper, powder morphology, size and size distribution (Fig. 1) as well as powder microstructure (Fig. 2a) have been of concern in optimizing reliable superconducting products. Residual microstructures, including grain boundaries (inter-particle interfaces), are also critical features which control or influence mechanical behavior as well as superconductivity (especially transport supercurrent).The fabrication process involves significant features of both explosive welding and explosive consolidation, and optimization requires optimizing the welding of the metal matrix and simultaneous consolidation of the superconducting powder. In a copper matrix, one important optimum seems to lie within a narrow region of explosive detonation velocity (VD) ranging from 1.8 to 2.2 km/s.

APA, Harvard, Vancouver, ISO, and other styles

8

Yakovleva, S. P., S. N. Makharova, M. I. Vasilyeva, and A. V. Ptitsyna. "Wear resistance factors of diamond-metal powder systems, obtained by explosive compaction." Procedia Structural Integrity 20 (2019): 190–97. http://dx.doi.org/10.1016/j.prostr.2019.12.138.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Saikov, Ivan V., Andrey Yu Malakhov, Vitaliy G. Salamatov, Stepan A. Seropyan, Ilya E. Semenchuk, and D. Yu Kovalev. "Synthesis in SHS-Mixtures by Explosive Loading." Key Engineering Materials 839 (April 2020): 114–18. http://dx.doi.org/10.4028/www.scientific.net/kem.839.114.

Full text

Abstract:

The article is devoted to the study of the characteristics of shock-wave processing of powder mixtures capable of an exothermic reaction of the synthesis of metal-ceramic materials. Experiments on shock-wave initiation of synthesis in systems based on Ti-B and Ti-C with 10% and 20% Ni content were carried out. Explosive loading was carried out by oblique throwing of a steel drummer with speeds of 1000 m / s and 1500 m / s. X-ray phase analysis of synthesis products showed the presence of TiB2 diboride and TiC carbide in the nickel bond. The significant role of the mechanical activation of powder mixtures in increasing the sensitivity of SHS-mixtures to shock-wave loading is shown.

APA, Harvard, Vancouver, ISO, and other styles

10

Vlasov, Viktor A., Yurii F. Ivanov, Gennady Volokitin, Anton D. Teresov, and Anatolii A. Klopotov. "Structure and Property Coating Modification by High Energy Density." Advanced Materials Research 1013 (October 2014): 153–57. http://dx.doi.org/10.4028/www.scientific.net/amr.1013.153.

Full text

Abstract:

The paper reviews the results of investigations of the surface layer structure and properties of type 35-L steel and commercially pure titanium modified by plasma flows (arc plasma torch with the powder blown into an arc), electro-explosive alloying of titanium specimens, and high energy electron-beam treatment performed on the vacuum electron-beam plant SOLO. It is shown that the surface treatments under review have lead to a multilayer and multi-phase structure formed by crystalline particles of sub-microsized and nanosized range, mechanical (microhardness) and tribological (wear resistance) properties of which exceed manifold that of the substrate material.

APA, Harvard, Vancouver, ISO, and other styles

11

Khaustov, S. V., A. V. Krokhalev, V. O. Kharlamov, M. A. Tupitsin, S. V. Kuz’min, and V. I. Lysak. "Experimental determination and calculation of powder mixture heating temperature at explosive compaction." Izvestiya Vuzov. Poroshkovaya Metallurgiya i Funktsional’nye Pokrytiya (Universitiesʹ Proceedings. Powder Metallurgy аnd Functional Coatings), no. 3 (September 16, 2018): 23–29. http://dx.doi.org/10.17073/1997-308x-2018-3-23-29.

Full text

Abstract:

The paper presents the experimentally determined heating temperature of mixed chromium carbide powders and titanium bond under explosive loading on a metal substrate. Pressure of powder mixture compression in shock waves during explosive pressing was 2,5 GPa. The experiment involved recording a thermal cycle on the back side of the coated metal substrate serving as a heat receiving element. It also solved a problem of non-stationary heat conduction until the calculated and experimental thermal cycles coincided. Initial conditions were chosen assuming that the compacted material is uniformly heated to a certain average temperature by the time the shock-wave processes end. Required thermophysical properties of the compacted material were determined by the laser flash method using the LFA 427 unit («Netzsch», Germany). According to calculations, powder mixture heating temperatures were 208 °C and 225 °C for adiabatic approximation and taking into account heat transfer into the environment, respectively. The obtained values were compared with ones calculated by the increase in enthalpy during the shock wave processing (these calculations used solid material densities under normal conditions and final powder material density determined after explosive treatment to be 199 °C and 220 °C, respectively), and it was found that they differ insignificantly. Thus, the assumption of equal material density in a shock wave and solid density does not lead to a significant error and can be used for practical calculations.

APA, Harvard, Vancouver, ISO, and other styles

12

Du, Chang Xing, Zheng Zhao, and Gang Tao. "Explosive Compaction-Coating Manufacture Large Area Coat." Advanced Materials Research 189-193 (February 2011): 1014–17. http://dx.doi.org/10.4028/www.scientific.net/amr.189-193.1014.

Full text

Abstract:

A new technology for manufacturing large area coating, named explosive compaction- coating (ECC), was proposed in this paper, and its concrete process was described in detail. The ECC for Cu plate- Cu powder was experimented, by variety height of burst and heat treatment of Cu plate four groups divided into, and uniform coating thickness beyond 300 um was obtained. Research shows that the optimal impact velocity is 900 m/s. Annealing treatment of Cu plate has not impact on coating. ECC can manufacture large area metal or nonmetal coating and nano or amorphous coating.

APA, Harvard, Vancouver, ISO, and other styles

13

Liu, Zhi-Yue, Katsumi Tanaka, and Shigeru Itoh. "A Method for Producing Extra-High Dynamic Pressure Due to the Efficient Use of High Explosive." Journal of Pressure Vessel Technology 126, no. 2 (2004): 264–68. http://dx.doi.org/10.1115/1.1687384.

Full text

Abstract:

In the material processing such as shock synthesis and powder consolidation by shock waves the method for generating dynamic pressure is a vital factor for the quality of the final recovered materials. A general and convenient way for producing shock wave demanded in such applications is to take advantage of the explosion effect from high explosive. Under normal conditions, a given high explosive can only provide some kind of magnitude of dynamic pressure after its explosion. Therefore, it is whether possible to obtain the higher dynamic pressure by adequately changing the form of the explosion of high explosive. Starting from this motivation, we put forward a new method for producing high dynamic pressure from the use of the overdriven detonation of high explosive. The proposed device consists of the following configurations. A metal flyer accelerated by the high explosive is used to impact another layer of high explosive to incur an overdriven detonation in this layer of explosive. The overdriven detonation of high explosive acts on the powder materials, bringing out high dynamic pressures to the materials studied. To examine the efficiency of this combination on the improvement of dynamic pressure, a numerical computation is performed on this system. The details on the illustration of this method as well as the results of numerical investigation will be given.

APA, Harvard, Vancouver, ISO, and other styles

14

Gao, Juxian, Binghuang Shao, and Ke Zhang. "A study of the mechanism of consolidating metal powder under explosive‐implosive shock waves." Journal of Applied Physics 69, no. 11 (1991): 7547–55. http://dx.doi.org/10.1063/1.347572.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

Japaridze, Levan, Akaki B. Peikrishvili, Laszlo J. Kecskes, et al. "Hot Explosive Consolidation of WC-AlNi Composites." Advances in Science and Technology 45 (October 2006): 905–16. http://dx.doi.org/10.4028/www.scientific.net/ast.45.905.

Full text

Abstract:

WC + Ni-clad Al, Ni(Al), powder mixtures were formed into cylindrical rods or tubes using a hot explosive consolidation (HEC) process. During HEC, the Ni(Al) precursor, in the WC + Ni(Al) mixture, was found to react to form a WC-AlNi composite structure. The composite consisted of WC particles dispersed in a matrix of Al-Ni intermetallic phases. The consolidation temperature was varied from room temperature to 800°C; the shock loading intensity was as high as 10 GPa. The investigation showed that the combination of high temperatures and explosive compression was beneficial to the consolidation of the WC-AlNi composites, resulting in high densities, good integrity, and the formation of transient layer between the sample and the steel container’s wall. The structure and property of the samples obtained, and the formation of the transient layer depended on the shock loading conditions and the consolidation temperature. Features of the consolidated WC-AlNi samples as a function of the loading conditions (experimental set-up, loading intensity, and preheating temperature) are discussed.

APA, Harvard, Vancouver, ISO, and other styles

16

Ahn, Ji Young, Whi Dong Kim, Kuk Cho, Donggeun Lee, and Soo Hyung Kim. "Effect of metal oxide nanostructures on the explosive property of metastable intermolecular composite particles." Powder Technology 211, no. 1 (2011): 65–71. http://dx.doi.org/10.1016/j.powtec.2011.03.033.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Krokhalev, A. V., V. O. Kharlamov, S. V. Kuzmin, and V. I. Lysak. "FUNDAMENTALS OF WEAR-RESISTANT COATING PRODUCTION FROM CHROMIUM CARBIDE POWDER MIXTURE WITH BINDER METAL BY EXPLOSIVE COMPACTION." Izvestiya Vuzov Tsvetnaya Metallurgiya (Proceedings of Higher Schools Nonferrous Metallurgy, no. 3 (June 14, 2018): 68–83. http://dx.doi.org/10.17073/0021-3438-2018-3-68-83.

Full text

Abstract:

The article presents experimental data on explosive compaction of chromium carbide (Cr3C2) powder mixtures with metals (Ti, Ni, Cu) provided with theoretical explanations. These data were used as a basis for stating science-based principles of composition selection and technology development to produce antifriction wear-resistant chromium carbide hard alloys and coatings by explosion. Explosive compaction of powder mixtures was carried out according to a scheme using a normally incident plane detonation wave in a wide range of loading parameters (powder heating temperature in shock waves varied from 200 to1000 °Cand maximum shock compression pressure varied from 4 to 16 GPa during experiments). Phase transformation analysis was carried out by the numerical thermodynamic modeling of phase equilibrium using the Thermo-Calc software. Microstructure, chemical and phase compositions were studied using optical («Axiovert 40МАТ» by CarlZeiss,Germany), scanning («Versa 3D» and «Quanta 3D FEG» byFEI,USA), transmission («BS 540» byTesla,Czech Republic, «Titan 80-300» and «Tecnai G2 20F» byFEI,USA) electron microscopes and «Solver Pro» atomic force microscope (LLC «NT-MDT», Zelenograd). Temperature stability and oxidation resistance at elevated temperatures of the materials obtained by explosion was studied using thermogravimetric analysis (TGA) using the «STA 449 F3 Jupiter» instrument (NETZSCH, Germany) in the synthetic air environment when heated to1500 °C. Tribological tests were carried out on the MI-1M friction machine (MEZIMiV,Moscow) according to the pin-on-ring scheme with plunging in distilled water environment. The mechanisms of consolidation and formation of strong boundaries between powder material particles during explosive compaction are described. It is shown that hard alloys of chromium carbide with titanium bond obtained by explosion retain their phase compositions without any changes and resist to oxidation up to600 °C, and also have significantly better anti-friction properties and wear resistance than the SGP-0,5 and KHN-20 materials used in water-lubricated friction couples until the present time.

APA, Harvard, Vancouver, ISO, and other styles

18

Tanaka, Shigeru, Kazuyuki Hokamoto, and Shigeru Itoh. "Shock Compaction of WC-Co Powder in Metallic Tube." Materials Science Forum 566 (November 2007): 333–38. http://dx.doi.org/10.4028/www.scientific.net/msf.566.333.

Full text

Abstract:

The tungsten carbide - cobalt, (WC-Co) powder is compacted and bonded to on a stainless steel (SUS304) rod by using explosives. In this research, the experiments are conducted using two methods. They are the method of making the pressure of the explosive act directly on the powder and the method of explosively driving a metal pipe with high speed to create high pressure acting on powder. Crack free bulk material was recovered. Heat-treatment was performed on the recovered sample. After heat treatment, the value of hardness was increased compared with commercial material.

APA, Harvard, Vancouver, ISO, and other styles

19

Krokhalev, A. V., V. O. Kharlamov, D. R. Chernikov, S. V. Kuzmin, and V. I. Lysak. "FUNDAMENTALS OF TECHNOLOGY FOR OBTAINING WEAR-RESISTANT HARD ALLOY POWDER COATINGS BY EXPLOSION." IZVESTIA VOLGOGRAD STATE TECHNICAL UNIVERSITY, no. 7(254) (July 22, 2021): 7–21. http://dx.doi.org/10.35211/1990-5297-2021-7-254-7-21.

Full text

Abstract:

An overview of the results of an experimental study of the effect of the type and content of the metal binder, the parameters of shock-wave compression and subsequent heating on the formation of hard alloys and coatings from them during the explosive treatment of CrC-Ti powder mixtures on steel substrates is presented, the mechanism of wear and antifriction properties of the obtained materials is described.

APA, Harvard, Vancouver, ISO, and other styles

20

Wang, Zhi Ling. "Study on Microstructure and Mechanical Properties of Explosive Welding Composite Plate." Key Engineering Materials 723 (December 2016): 258–61. http://dx.doi.org/10.4028/www.scientific.net/kem.723.258.

Full text

Abstract:

We used the Q345R/ composite panels by explosive composite method,and studied the microstructure and properties of the composite plate by the means of optical microscope and mechanical property test in this paper. We can see that the interface of explosive composite board is in a wave shape, the microstructure in the region next to the bonding interface of the composite plate consists of three parts: distorted grain area, fibrous zone and fine grained region. The composite explosive plate is still of high tensile strength and ductility, and its impact absorbing energy is to 68J, the hardness of the interface for the composite plate of 304 is higher and rise more remarkable than the base metal of Q345R.

APA, Harvard, Vancouver, ISO, and other styles

21

Kharlamov, V. O., Aleksandr Vasilevich Krokhalev, S. V. Kuz’min, and V. I. Lysak. "Formation of Hard Alloys of Chromium Carbide and Titanium Powder Mixtures by Explosive Pressing." Key Engineering Materials 684 (February 2016): 193–97. http://dx.doi.org/10.4028/www.scientific.net/kem.684.193.

Full text

Abstract:

The production of a new type of hard alloys by explosive compaction of chromium carbide (Cr3C2) and titanium powder mixtures was investigated. The phase composition of the fabricated alloys was studied using scanning electron probe microanalysis. The chemical composition of the alloy components does not change, and no redistribution of the elements was observed. The formation characteristics of the interfaces between the material components during shock wave processing were investigated using electron microscopy. The explosion compaction of high melting carbide and metal powder mixtures results in the formation of consolidated hard alloys during the compaction stage.

APA, Harvard, Vancouver, ISO, and other styles

22

Wu, Hong-Chun, Hsin-Jung Ou, Deng-Jr Peng, Hsiao-Chi Hsiao, Chung-Yun Gau, and Tung-Sheng Shih. "Dust Explosion Characteristics of Agglomerated 35 nm and 100 nm Aluminum Particles." International Journal of Chemical Engineering 2010 (2010): 1–6. http://dx.doi.org/10.1155/2010/941349.

Full text

Abstract:

In the experiment, nanoparticles of 35 nm Al and 100 nm Al powders, respectively, formed particles with average sizes of 161 nm and 167 nm in agglomeration. The characteristics of dust cloud explosions with the two powder sizes, 35 nm and 100 nm, revealed considerable differences, as shown here: (dp/dt)max-35 nm= 1254 bar/s, (dp/dt)max-100 nm= 1105 bar/s; Pmax-35 nm= 7.5 bar, Pmax-100 nm= 12.3 bar, and MEC-35 nm= 40 g/m3, MEC-100 nm= 50 g/m3. The reason of Pmax-35 nmvalue is smaller than Pmax-100 nmmay be due to agglomeration. From an analysis of the explosive residue, the study found that nanoparticles of 35 nm Al powder became filamentous strands after an explosion, where most of 100 nm Al nanoparticles maintained a spherical structure, This may be because the initial melting temperature of 35 nm Al is 435.71°C, while that for 100 nm Al is 523.58°C, higher by 87.87°C. This study discovered that explosive property between the 35 nm Al and 100 nm Al powders after agglomeration were different.

APA, Harvard, Vancouver, ISO, and other styles

23

Kira, Akio, Kazuyuki Hokamoto, Yasuhiro Ujimoto, Shoichiro Kai, and Masahiro Fujita. "Collection of Product Synthesized Using Extremely High Impulsive Pressure Generator." Materials Science Forum 566 (November 2007): 315–20. http://dx.doi.org/10.4028/www.scientific.net/msf.566.315.

Full text

Abstract:

A new method has been developed to generate an extremely high impulsive pressure by using a metal jet that is discharged when a metal collides with another metal. The high pressure is used to synthesize a new material. When a metal plate was accelerated by the detonation of an explosive, it collides with the concentric circle of the conic surface of a conical concave metal block metal jets are discharged from all parts on the concentric circle. The metal jets fly toward the center while converging and collide with each other at the central axis. Because those collide at high-speed pressure becomes extremely high. The flight direction of the converged metal jet changes downward. The metal jet collides with the bottom of the block. A large hole is formed inside the bottom. The formation process of the hole was examined by the observation of the section of the block. A specimen powder that was rubbed to the conic surface is discharged with the metal jet and become the high pressure. The specimen powder is synthesized to a different material. The synthesized material is held inside the formed hole. The existence of cBN was confirmed by the X-ray diffraction of the synthesized material, in the case that BN was used as the specimen powder. Similarly, the existence of diamond was confirmed in the case of graphite powder.

APA, Harvard, Vancouver, ISO, and other styles

24

MATSUDA, Yusuke, Katsumi OKAMURA, and Tomohiro FUKAYA. "E04 Property of CBN compact for ferrous powder metal and cast iron machining." Proceedings of The Manufacturing & Machine Tool Conference 2012.9 (2012): 259–60. http://dx.doi.org/10.1299/jsmemmt.2012.9.259.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Jeon, Jin Woo, Jeong Hwan Yun, Myeong Sik Jeong, et al. "Metal Powder Injection Molding Process for Manufacturing Adapter Component." Key Engineering Materials 622-623 (September 2014): 868–75. http://dx.doi.org/10.4028/www.scientific.net/kem.622-623.868.

Full text

Abstract:

Adapters are a component of the output system in the internally geared hub for a bicycle. Originally, adapter parts were produced by a machining process with low productivity and material usage rate. In this study, the metal powder injection molding (MIM) process has been applied as an alternative manufacturing method to the machining process. Microstructure analysis and mechanical property testing has been conducted in order to select the material for the adapter with changes in the nickel content. The geometrical precision of the adapter is measured by using three-dimensional scanner with various mixing ratios of the powder and the binder. The developed alternative process for the adapter results in increased productivity and material usage rate. Previously, this process was only used for small parts less than 10 mm in diameter. With this development, the MIM process may be used more widely than before.

APA, Harvard, Vancouver, ISO, and other styles

26

Lee, Sang Jin, Chung Hyo Lee, and S. Y. Chun. "Organic-Inorganic Solution Technique for Fabrication of Porous CaO-SiO₂ Based Powders." Key Engineering Materials 287 (June 2005): 117–22. http://dx.doi.org/10.4028/www.scientific.net/kem.287.117.

Full text

Abstract:

Soft and porous CaO-SiO2 powders (CaSiO3, Ca2SiO4, Ca3SiO5) were fabricated by organic-inorganic solution technique. Calcium nitrate and Ludox SK silica sol were dissolved in D.I. water and then 5 wt% polyvinyl alcohol solution was added as a polymeric carrier. The metal cations were dispersed well in solution and a homogeneous polymeric network was formed. The organic-inorganic precursor gels were turned to porous powder having volume expansion through an explosive oxidation reaction during calcination process. The polyvinyl alcohol content and heating rate were affected on the explosive reaction behavior. It may be speculated that the reaction between oxygen and unstable calcium cations resulted in the vigorous exothermic reaction and simultaneously the reaction made extensive void, which is accompanied with volume expansion in the powder structure, by the thermal decomposition in a moment of organic substance, polyvinyl alcohol. The porous powders were crystallized at relatively lower temperatures, and the crystalline development was dependent on the polymer content.

APA, Harvard, Vancouver, ISO, and other styles

27

Zhou, Hui Sheng, Xing Hua Xie, Shao Bo Yan, and Zeng Yuan Li. "Ceramic Oxides from Liquid Explosive Reaction." Key Engineering Materials 807 (June 2019): 176–81. http://dx.doi.org/10.4028/www.scientific.net/kem.807.176.

Full text

Abstract:

This investigation promotes the design of emulsion explosives and the development of detonation theory on a microscale. As the total composition of oxidizing and reducing elements of the reactants leave related to the thermochemistry of the system, the computational details of predicting the temperatures of detonation were introduced. It was found that a significant improvement was achieved in the emulsion explosives with an aquiferous system. An improvement in the detonation synthesis of nanolithium and zinc oxides is due to the formation of an activated matrix of the metal nitrates’ oxidizer with the corresponding fuel. Temperatures of detonation of emulsion explosives and explosive formulations are predicted using thermochemistry information. The methodology assumes that the heat of detonation of an explosive compound of composition CaHbNcOdLieZnf can be approximated as the difference between the heats of formation of the detonation products and that of the explosive, divided by the formula weight of the explosive. For the calculations in which the first set of decomposition products is assumed, predicted temperatures of detonation of emulsion explosives with the product H2O in the gas phase have a deviation of 413.66 K from results with the product H2O in the liquid state. Fine-particle lithium and zinc oxides have been prepared by the detonation of emulsion explosives of the metal nitrates, M (NO3) x (M = Li, Zn) as oxidizers and paraffine as fuels, at high temperature and short reaction time. The detonation products were identified from X-ray powder diffraction (XRD) patterns, and transmission electron microscopy (TEM) measurements. XRD analysis shows that nanoparticles of lithium and zinc oxides can be produced from detonation of emulsion explosives due to fast quenching as well as appropriate detonation velocity and temperature.

APA, Harvard, Vancouver, ISO, and other styles

28

Wang, Yan Hui, Qi Liu, Xin Wei Bo, Xiao Yu Wang, Chun Dong Jiang, and Rui Tang. "The Study on Sintering Capabilities of High Purity Metal Vanadium Powder." Key Engineering Materials 807 (June 2019): 31–36. http://dx.doi.org/10.4028/www.scientific.net/kem.807.31.

Full text

Abstract:

High purity metal vanadium powder was milled by high energy ball milling, and the grain size and morphology of vanadium powder was observed by electron probe, and the stress-strain curve was measured by CMT5305 universal testing machine for research of the mechanical property. In order to investigate the effect of sintering process on the property of product, the vanadium powder was sintered by the hot pressing sintering process and the cold isostatic pressing with vacuum sintering process respectively. The experimental results show that for the cold isostatic pressing with vacuum sintering process, the density of raw compact increases with the increase of pressing pressure. When the pressure increases to 280 MPa, the density and relative density of raw compact are 3.99 g·cm-3 and 66.94% respectively, the density and relative density of product after sintering are 5.28 g·cm-3 and 88.59% respectively. With the pressure increasing from 80 MPa to 200 MPa, the compressive strength increases significantly from 0.4 MPa to 6.0 MPa, the pressure increases to 280 MPa, the compressive strength slowly increases to 7.4 MPa. For the hot pressing sintering process, the relative density of product is higher than that of cold isostatic pressing with vacuum sintering process, and the density and relative density reach to 5.51 g·cm-3 and 92.91% respectively under 280 MPa pressure.

APA, Harvard, Vancouver, ISO, and other styles

29

Xie, Xing Hua, Chun Yang Dai, and Hui Sheng Zhou. ""321" Incident Iron Ions Characteristics and Catalytic Mechanism of Thinking." Advanced Materials Research 1082 (December 2014): 395–98. http://dx.doi.org/10.4028/www.scientific.net/amr.1082.395.

Full text

Abstract:

Compatibilityand safety systems research and production equipment itself explosives mixedvehicle technology between the establishment and development of the explosionmechanism of explosive accidents and prevent the occurrence of accidentalexplosion of explosives to achieve disaster prevention and reduction, to ensurethe safety of personnel and minimize property damage. Research explosives mixedvehicle production equipment commonly used in metal and alloys in aqueousammonium nitrate system compatibility, especially at higher temperatures and avariety of elements, such as the case of explosives from the synergies toaccelerate the reaction conditions, choose good compatibility the materials toimprove the production of mixed explosive nature of car safety, to solve theproduction of explosives explosion problem.

APA, Harvard, Vancouver, ISO, and other styles

30

Kira, Akio, Yoshiaki Tsutsumi, Akio Tasaka, Ryuichi Tomoshige, Kazuyuki Hokamoto, and Masahiro Fujita. "Generation of Ultrahigh Pressure and Application of Ultrahigh Pressure to Formation of Diamond from Graphite Powder." Materials Science Forum 673 (January 2011): 275–78. http://dx.doi.org/10.4028/www.scientific.net/msf.673.275.

Full text

Abstract:

The purpose of our research is to generate the ultrahigh pressure by using high explosive and to transform a phase of a material. The extremely high impulsive pressure generator that has been developed by us uses the head-on collision between metal jets. Because the velocity of the metal jet is very high, the ultrahigh pressure will generate. If a powdered material is mixed to metal jets, it is expected that the material is transformed to a high pressure phase by this ultrahigh pressure. A graphite powder was used to synthesize a diamond. The existence of the diamond was confirmed by X-ray diffraction (XRD). In this paper, the mechanism of the generation of the ultrahigh pressure is explained and the results of the observation of the powder by using scanning transmission electron microscope (STEM) are reported.

APA, Harvard, Vancouver, ISO, and other styles

31

Li, Yu-Ling, Yu-Fei Wang, Li-Ping Zheng, Xiao-Li Zhou, and Jing-Jing Li. "Synthesis, structure and selective adsorption property of Zn metal-organic framework." E3S Web of Conferences 53 (2018): 01034. http://dx.doi.org/10.1051/e3sconf/20185301034.

Full text

Abstract:

Zn metal-organic framework material [Zn2(tib)(HBTB)2(H2O)]·2H2O (1) [tib = 1,3,5-tris(1- imidazolyl)benzene, H3BTB = 4,4′,4″-benzene-1,3,5-triyl-tribenzoic acid] was synthesized and characterized by Thermogravimetric analyses (TGA), Powder X-ray diffraction (PXRD) analyses and Bruker D8 Advance X-ray diffractometer. The results showed that 1 was a 2D network to be joined together by hydrogen bonds to generate a 3D supramolecular structure. Gas, vapor adsorption behavior of the material was studied. It is meaningful that 1 can selective sorption of CO2 and MeOH.

APA, Harvard, Vancouver, ISO, and other styles

32

Yao, Wen Jin, Xiao Ming Wang, Wen Bin Li, and Xiao Hui Gu. "Effect of Carbon Fiber Composite Material Casing on Blast Power of Explosive Charge." Advanced Materials Research 79-82 (August 2009): 461–64. http://dx.doi.org/10.4028/www.scientific.net/amr.79-82.461.

Full text

Abstract:

A new kind of low collateral damage ammunition with Carbon fiber composite material casing is put forward. The operational principle of this ammunition and its configuration are introduced. Then the casting velocity of lethal unit and air shock wave pressure is analyzed theoretically and simulated. In order to study the effect of casing material on blast power, two different kinds of explosive charges are detonated. Overpressure curve of these two charges is measured using the pressure sensors. From the measured overpressure curve and theoretical simulation results, the duration of the positive pressure of the air blast pressure wave caused by the prototype model of the low collateral damage ammunition is bigger than the explosive charge with Carbon fiber composite material casing and naked explosive charge. From the high speed photography, the lethal units flight to a halt at a small distance. These results show the explosive charge with Carbon fiber composite material casing and metal powder can reduce destruction outside the radius of an intended target while enhancing its destructive force on the target.

APA, Harvard, Vancouver, ISO, and other styles

33

Nováček, Petr, and Jakub Svatoš. "Intelligent Metal Detector." Key Engineering Materials 543 (March 2013): 133–36. http://dx.doi.org/10.4028/www.scientific.net/kem.543.133.

Full text

Abstract:

Humanitarian demining is a matter of high interest, but metal contamination and magnetic soils reduce the sensitivity of metal detectors. The soil contamination also increases the numbers of false alarms which, in some areas, account for as much as 99.9 % of all alarms. The decrease of false alarms is therefore attractive. Our solution is capable to be adapted and utilized with current professional metal detectors. Essentially it consists of several modules with modular structure, where the master module is always necessary in all applications and the navigation module has to be connected in cases where position estimation is required. Searching part of the detector is able to work in continuous wave mode with variable excitation signal and the possibility to utilize more carrier frequencies. Furthermore, the modular structure can use different search heads available on the market as well as heads developed for special purposes. The modular metal and mine detector described is capable to detect not only unexploded ordnance and explosive remnants of wars, but also pipes and wires in walls and floors indoor which is useful property during not only buildings reconstructions.

APA, Harvard, Vancouver, ISO, and other styles

34

Qin, Qun, and Guang Xia Chen. "Microstructure and Mechanical Property Analysis of the Metal Part by SLM." Applied Mechanics and Materials 423-426 (September 2013): 693–98. http://dx.doi.org/10.4028/www.scientific.net/amm.423-426.693.

Full text

Abstract:

The objective of the research was that analyzed the microstructure and mechanical properties of metal part built by SLM in this paper. The tensile samples were made by SLM, the rupture gotten with tensile experiment was scan by SEM, and the rupture property was analyzed. The results of experiment showed: the parts formed by optimized parameters have a density above 96%, a tensile strength of 635MPa, an extension of 55.679% and an average micro hardness of HV307 for stainless steel powder. It is interesting to find that the phase of the built parts is also austenite by XRD, which is the same as that of the starting material.

APA, Harvard, Vancouver, ISO, and other styles

35

Yin, Jun Hui, Chao Xiong, Hui Yong Deng, and Yan Long Zhang. "Study on Evolution of Plastic Deformation of Brass Band under Impact Load." Key Engineering Materials 753 (August 2017): 222–27. http://dx.doi.org/10.4028/www.scientific.net/kem.753.222.

Full text

Abstract:

During the moving stage of the projectile, the impact load produced by the detonation of the explosive powder acts on the ribbon, causing the plastic band deformation to occur rapidly and the surface temperature rapidly increases. In this paper, the evolution mechanism of the plastic deformation of brass band is studied, and the recrystallization process of the surface metal is still at the meso-scale scale. The recrystallization and grain growth stage sexual characteristics.

APA, Harvard, Vancouver, ISO, and other styles

36

Nishiyabu, Kazuaki, Satoru Matsuzaki, Kenji Okubo, Masashi Ishida, and Shigeo Tanaka. "Porous Graded Materials by Stacked Metal Powder Hot-Press Moulding." Materials Science Forum 492-493 (August 2005): 765–70. http://dx.doi.org/10.4028/www.scientific.net/msf.492-493.765.

Full text

Abstract:

The production method for metal components with micro sized porous structure has been developed by applying “powder space holder method” to metal powder injection molding process. In this study, a co-sintering process was utilized to make a plate of sintered metal with micro porous graded structure. The green compact sheets with various contents of space hold particles were prepared by hot press molding for simplification. The five layers of metal with symmetric structure, which the skin layer was formed with high density metal and the core was formed with open or closed porous structure, or with inverse symmetry, was obtained by changing stacking sequence in co-sintering process. Mechanical properties of the materials with plain homogeneous porous structure and porous graded structure were compared. The usefulness of proposed method for producing the metal components with micro porous graded structure and the effective of graded structure to compensate the deficiencies on the mechanical property of porous metals was shown.

APA, Harvard, Vancouver, ISO, and other styles

37

Mustofa, Salim, Patricius Purwanto, and Wisnu Ari Adi. "The influence of layer thickness on the electrical property of metal-CNT (metal: Cu) composite." Malaysian Journal of Fundamental and Applied Sciences 14, no. 4 (2018): 509–11. http://dx.doi.org/10.11113/mjfas.v14n4.1240.

Full text

Abstract:

The composite of Metal – MWCNT (Metal: Cu) were made by using solid-state reaction method for 1 hour at R.T. after mixing the Multiwalled - CNT (MWCNT) and Copper (Cu) powder with 3% weight of Cu. The result of electrical property measured using LCR meter indicated that the conductivities value of MWCNT/Cu was increased in proportion to the increase of layer thickness of composite and the increasing of frequency measurement. On the other hand, the capacitance value of the MWCNT/Cu composite sample was decreased by the increasing of frequency measurement. From the analysis of cole-cole plot, the MWCNT/Cu composite indicated the peak maximum at certainl frequency, which shows the possibility of achievable polarizability. We have measured the Raman spectra of MWCNT/Cu composites to evaluate the state of dispersion and the Cu-filler interactions reflected, by shifts changes of the peaks. All the Raman bands of the carbon nanotubes are seen at wave number around of 1326 cm-1 (D band), and a wave number around of 1617 cm-1 (second harmonic G band).

APA, Harvard, Vancouver, ISO, and other styles

38

Sun, Jun Sheng, En Li Jiao, Hao Meng Wang, and Yi Qun Sun. "The Design and Application of the Ultra-Thick Abrasion Resistant Flux-Cored Wire." Advanced Materials Research 507 (April 2012): 127–31. http://dx.doi.org/10.4028/www.scientific.net/amr.507.127.

Full text

Abstract:

In this paper, a type of high efficient ultra-thick high-chromium cast iron surfacing flux-cored wire of a diameter of 6mm is designed to solve the technological problem that the processing property of ultra-thick flux-cored wire can not meet the welding requirement, and “inter twist connection” and “inner wire” technologies were adopted. The effect of alloying elements Cr and C in the powder on the microstructure and property of deposited metal was researched. The results showed that when Cr content is 39% and C content is 5.7% in the powder, the microstructure of deposited metal is nearly eutectic, of which the hardness and wear resistance are higher. The test of engineering application of surfacing was carried out on bucket in wheel loader. It is proved that the wear-resisting property and the service life of the bucket can be significantly improved.

APA, Harvard, Vancouver, ISO, and other styles

39

Amuda, M. O. H., F. T. Lawal, M. A. Onitiri, E. T. Akinlabi, and S. Mridha. "Microstructure and Mechanical Properties of Metal Powder Treated AISI-430 FSS Welds." International Journal of Manufacturing, Materials, and Mechanical Engineering 8, no. 4 (2018): 63–83. http://dx.doi.org/10.4018/ijmmme.2018100104.

Full text

Abstract:

An innovative yet simple technique for the inoculation of the weld pool of commercial AISI 430 Ferritic Stainless Steel (FSS) with metal powders for grain refinement is discussed. Aluminum or titanium powder in varying amounts introduced into the weld pool via a powder preplacement technique was melted under a tungsten inert gas (TIG) torch. This strategy of inoculating the welds offers dual benefits of grain refinement and constriction in the weld geometry. The addition of the metal powders constricts the HAZ by as much as 50% of the conventional weld providing a grain refinement index (GRI) of about 0.8 in titanium powder treated welds. It equally emerged that weld property is not influenced by the grain size alone but equally by the amount of delta ferrite in the microstructure.

APA, Harvard, Vancouver, ISO, and other styles

40

Kira, Akio, Ryuichi Tomoshige, Kazuyuki Hokamoto, and Masahiro Fujita. "Phase Transformation of Powdered Material by Using Metal Jet." Materials Science Forum 706-709 (January 2012): 741–44. http://dx.doi.org/10.4028/www.scientific.net/msf.706-709.741.

Full text

Abstract:

The various techniques of phase transformation of the material have been proposed by many researchers. We have developed several devices to generate the ultrahigh pressure by using high explosive. One of them uses metal jets. It is expected that the ultrahigh pressure occurs by the head-on collision between metal jets, because the velocity of the metal jet is very high. By mixing a powdered material with metal jets, the pressure of the material becomes high. The purpose of this study is to transform the phase of the powdered material by using this high pressure. The powders of the graphite and hBN were applied. The synthesis to the diamond and cBN was confirmed by X-ray diffraction (XRD). In this paper, the mechanism of the generation of the ultrahigh pressure is explained and the results of the observation of the powder by using scanning transmission electron microscope (STEM) are reported.

APA, Harvard, Vancouver, ISO, and other styles

41

Li, Xiao Jie, Xing Hua Xie, Long Jiang Zou, et al. "Ultrafine Oxides during Detonation Expanse at A Fast Quenching Rate." Key Engineering Materials 324-325 (November 2006): 189–92. http://dx.doi.org/10.4028/www.scientific.net/kem.324-325.189.

Full text

Abstract:

Nanostructured spherical lithium manganese oxide (Li-Mn-O) with about 30nm in diameter was synthesized for the first time by explosive method. The water-solubility explosive was prepared using a simple facility at room temperature. The growth of lithium manganese oxides via detonation reaction was investigated with respect to the presence of an energetic precursor, such as the metallic nitrate and the degree of confinement of the explosive charge. The detonation products were characterized by scanning electron microscopy. Powder X-ray diffraction and transmission electron microscopy were used to characterize the products. Lithium manganese oxides with spherical morphology and more uniform secondary particles, with smaller primary particles of diameters from 10 to 50 nm and a variety of morphologies were found. Lithium manganese oxides with a fine spherical morphology different from that of the normal is formed after detonation wave treatment due to the very high quenching rate. It might also provide a cheap large-scale synthesis method. Explosive detonation is strongly nonequilibrium processes, generating a short duration of high pressure and high temperature. Free metal atoms are first released with the decomposition of explosives, and then theses metal and oxygen atoms are rearranged, coagulated and finally crystallized into lithium manganese oxides during the expansion of detonation process. For detonation of the water-solubility explosive, the detonation pressure, the detonation temperature and the adiabatic gamma were close to 3 GPa, 2300 K and 3. The inherent short duration, high heating rate (1010 – 1011 K/s) and high cooling rate (108 – 109 K/s) prevent the lithium manganese oxides crystallites from growing into larger sizes and induce considerable lattice distortion.

APA, Harvard, Vancouver, ISO, and other styles

42

Fujiwara, Hiroshi, Ryota Akada, Yuki Yoshita, and Kei Ameyama. "Microstructure and Mechanical Property of Nano-Duplex Materials Produced by HRS Process." Materials Science Forum 503-504 (January 2006): 227–32. http://dx.doi.org/10.4028/www.scientific.net/msf.503-504.227.

Full text

Abstract:

An SUS316L and a Ti-6Al-4V alloy powders are treated by Mechanical Milling (MM) process, which is one of SPD processes, and then sintered by Hot Roll Sintering (HRS) process. The HRS process consolidates powder by hot rolling of an evacuated metal pipe filled with the powder at elevated temperatures. Those MM powders have a heavy deformed microstructure at the surface region and have a work hardened microstructure in the core region of the powder. In the surface region, a nano grain structure forms after the MM treatment in both materials. In case of the SUS316L powder, such a nano grain structure consists of an equiaxed nano ferrite (􀁄) grains which has transformed from nano austenite (􀁊) grains. Volume fraction of the 􀁄 phase decreases with distance from the surface of powder. During HRS the (􀁄 + 􀁊) nano-duplex structure changes to (sigma (􀁖) + 􀁊) nano-duplex structure by transformation of the 􀁄 to the 􀁖 phase. Thus, the SUS316L HRS material consists of a hybrid structure. That is, a (􀁖 + 􀁊) nano-duplex structure at the powder shell region, and a work hardened 􀁊 structure in the powder core region. In case of the Ti-6Al-4V MM powder, though no remarkable transformation occurs, a heavy deformed shell and work hardened core hybrid structure is also produced in the powder. By HRS the Ti-6Al-4V MM powder demonstrates a hybrid structure consists of an equiaxed nano grain structure and a coarse martensite structure. These two HRS materials indicate superior mechanical properties. Mechanical properties are improved by the HRS process. The proof stress and tensile strength in the SUS316L HRS material are x3.8 and x2.1 of the SUS316L conventional material, respectively. In the Ti-6Al-4V HRS material, they are x1.7 and x1.5 compared to the Ti-6Al-4V conventional material.

APA, Harvard, Vancouver, ISO, and other styles

43

Kunimine, Takahiro, Ryusei Miyazaki, Yorihiro Yamashita, Yoshinori Funada, Yuji Sato, and Masahiro Tsukamoto. "Cladding of Stellite-6/WC Composites Coatings by Laser Metal Deposition." Materials Science Forum 941 (December 2018): 1645–50. http://dx.doi.org/10.4028/www.scientific.net/msf.941.1645.

Full text

Abstract:

This study aims to investigate the microstructure and hardness of multi-layered Stellite-6/WC metal-matrix composites coatings on metallic substrates cladded by laser metal deposition (LMD) for improvement of wear and corrosion resistances. As coating materials, Stellite-6 and WC-12wt.%Co powders were selected. Powder mixtures having various mixing-ratios of Stellite-6 and WC-12wt.%Co were provided vertically on S45C substrates by controlling powder feeding rates of the two powder feeders, individually. Stellite-6/WC composites which consist of three layers with different compositions were cladded on the S45C substrates by laser melting. Cross-sectional microstructure observation was carried out by using an optical microscope (OM). Vickers microhardness tests were conducted to evaluate hardness of the cladding layers and substrates. The experimental results demonstrate that hard multi-layered Stellite-6/WC metal-matrix composites coatings were successfully cladded on the S45C substrates. Property gradients in the Stellite-6/WC composites could be made due to the position-dependent chemical composition and microstructure made by controlling powder feeding rates of an LMD system.

APA, Harvard, Vancouver, ISO, and other styles

44

Yang, Hui, Guo Dong Zhang, and Yuan Mei Fei. "Study on Microstructure and Property of the SHS Welding Joint." Advanced Materials Research 590 (November 2012): 51–55. http://dx.doi.org/10.4028/www.scientific.net/amr.590.51.

Full text

Abstract:

With the self-designed welding powder formula,this experiment employed the SHS reaction to weld the base metal,which was steel Q235 here,then respectively used Olympus large-scale horizontal digital microscope to analyze the structure morphology of the welding seam's different regions,JEOL SEM to point-analyze and line-analyze elements' distribution near the the weld interface and HV-1000 CCD automatic measurement microscopic vickers hardness tester to measure the microhardness of the pure copper's welding seam.The experiment's result shows the hardness of different part of the welded joint varies largely,and that the join of alloy elements can increase the microhardness of the welding metal,and that the welding metal and base metal interdiffuse,grow and mix remarkably near the fusion line,realizing wonderful metallurgical bonding.

APA, Harvard, Vancouver, ISO, and other styles

45

Omine, Yukimasa, Takashi Gushi, Osamu Higa, and Shigeru Itoh. "Development and Improvement of the Experimental Apparatus Using the Underwater Shock Wave." Materials Science Forum 767 (July 2013): 256–60. http://dx.doi.org/10.4028/www.scientific.net/msf.767.256.

Full text

Abstract:

The underwater shock wave has been studied in the various fields. The application of this method can be used for a molding machining, a welding and an embossing in the metal processing [. Moreover, this processing method can be used for a pulverizing, a softening, and a sterilization in the food processing. The aim of this research is to make the rice powder using by the underwater shock wave without generating of heat [. Although the underwater shock wave is generated using an explosive, the handling of the explosive is extremely accompanied by danger. Therefore, we developed the electric discharging device made to generate the underwater shock wave. It is easier to carry on the experiment using this device than the experiment of an explosive. We developed a pressure vessel for generating the underwater shock wave in various fields. The developed pressure vessel has been improved by our research group. The pressure vessel made to generate the shock wave is manufactured from a new concept, and the coaxial cable is used for wiring of the device.

APA, Harvard, Vancouver, ISO, and other styles

46

Dadkhah, Mehran, Abdollah Saboori, and Paolo Fino. "An Overview of the Recent Developments in Metal Matrix Nanocomposites Reinforced by Graphene." Materials 12, no. 17 (2019): 2823. http://dx.doi.org/10.3390/ma12172823.

Full text

Abstract:

Two-dimensional graphene plateletes with unique mechanical, electrical and thermo-physical properties could attract more attention for their employed as reinforcements in the production of new metal matrix nanocomposites (MMNCs), due to superior characteristics, such as being lightweight, high strength and high performance. Over the last years, due to the rapid advances of nanotechnology, increasing demand for the development of advanced MMNCs for various applications, such as structural engineering and functional device applications, has been generated. The purpose of this work is to review recent research into the development in the powder-based production, property characterization and application of magnesium, aluminum, copper, nickel, titanium and iron matrix nanocomposites reinforced with graphene. These include a comparison between the properties of graphene and another well-known carbonaceous reinforcement (carbon nanotube), following by powder-based processing strategies of MMNCs above, their mechanical and tribological properties and their electrical and thermal conductivities. The effects of graphene distribution in the metal matrices and the types of interfacial bonding are also discussed. Fundamentals and the structure–property relationship of such novel nanocomposites have also been discussed and reported.

APA, Harvard, Vancouver, ISO, and other styles

47

Park, Tae-Min, Choong-Hwan Jung, Haejin Hwang, and Sang-Jin Lee. "Polymer Solution Route for Synthesis of Nano-Sized, SiO2 Based Ceramic Powders." Journal of Nanoscience and Nanotechnology 20, no. 7 (2020): 4498–501. http://dx.doi.org/10.1166/jnn.2020.17568.

Full text

Abstract:

Nano-sized SiO2 based powders were fabricated by a polymer solution technique. Nitrate metal sources and Ludox series silica sol were dissolved in D.I. water and then polyvinyl alcohol solution was added as a polymeric carrier. The metal cations were dispersed well in the solution and a homogeneous polymeric network was formed. The organic–inorganic precursor gels were turned to a porous powder with expanded volume through an explosive oxidation reaction during calcination process. The polymer molecular weight, polymer content and heating rate affected the particle agglomeration and size. The reaction between oxygen and unstable metal cations resulted in a vigorous exothermic reaction and simultaneously the reaction created extensive voids, which accompanied soft powders. The porous powders were crystallized at relatively lower temperature, and easily ground to a very fine powder having nano-sized particles. The crystalline development was also dependent on the polymer type, and the weak hydrogen bonding by optimum polymer content promoted homogeneous entrapment between the –(OH) hydroxyl groups and cations, which are solvates by water molecules.

APA, Harvard, Vancouver, ISO, and other styles

48

Zhang, Ying Jie, Li Xian Sun, and Fen Xu. "Synthesis, Crystal Structure and Luminescence Property on Cabazoly-Based Zinc Metal Organic Frameworks." Key Engineering Materials 727 (January 2017): 628–34. http://dx.doi.org/10.4028/www.scientific.net/kem.727.628.

Full text

Abstract:

A novel zinc metal organic frameworks, named ZnL(2,2′-bpy), has been successfully synthesized, serving 3,6-dicarboxylic-9-ethylcarbazole acid (H2L) as ligand. This kind of ZnMOFs was characterized by FI-IR, elemental analysis, SEM, powder X-ray diffraction and single crystal X-ray diffraction to illustrate the structures. TG analysis was applied to investigate the thermostability. Structural analysis demonstrates that ZnMOFs possess triclinic crystal structure which is a 1D chain that occurs distorted-octahedral coordination geometry. Furthermore, the luminescent performance of ZnMOFs is performed and discussed in detail. The results show that ZnMOFs can emit blue luminescence originating, which is assigned to the ligand-to-metal charge transfer (LMCT).

APA, Harvard, Vancouver, ISO, and other styles

49

Khavrov, G. D., V. V. Kaminski, N. V. Sharenkova, and A. A. Vinogradov. "Features of the Implementation of the Vegard’s Law in Thin Films of Rare Earth Elements Compounds." Key Engineering Materials 822 (September 2019): 795–800. http://dx.doi.org/10.4028/www.scientific.net/kem.822.795.

Full text

Abstract:

In this work, the fulfillment of Vegard's law in thin polycrystalline films Sm1-xGdxS and Sm1-xEuxS, obtained by the method of explosive evaporation of the powder in vacuum, is investigated. It is shown that compliance with the Vegard law in the manufacture of thin-film structures based on Sm1-xEuxS solid solutions is possible only with the same technological parameters of film deposition, in particular, the substrate temperature. In the case of the Sm1-xGdxS solid solutions, the law is observed only in the metal phase of the solid solutions, with x> 0.12.

APA, Harvard, Vancouver, ISO, and other styles

50

Liu, Wen Bin, Adu, Yu Guang Lv, et al. "Preparation and Luminescent Properties of the La³⁺ Doped Tb³⁺-Hydroxyapatite." Applied Mechanics and Materials 716-717 (December 2014): 32–35. http://dx.doi.org/10.4028/www.scientific.net/amm.716-717.32.

Full text

Abstract:

In this paper, a rare earth metal terbium ion as the central metal ion, a nanohydroxyapatite powder of the lanthanum doped terbium was synthesis by precipitation with hydroxyapatite as ligand. The sample was characterized by infrared spectrum, fluorescence spectrum and X ray diffraction instrument, and the thermal properties and fluorescence properties, structure of powderes were discussed. A nanohydroxyapatite powder of the lanthanum doped terbium achieves the maximum luminous intensity, when the La3+ doping concentration of Tb3+ was HAP 5% (La3+ and Tb3+ mole fraction ratio) devices. Rare earth powder of the lanthanum doped terbium hydroxyapatite has the stability chemical properties, the luminescence properties and good biological activity, the rare earth powder has good luminescent properties can be used in preparation of a good light emitting device. At the same time a nanohydroxyapatite powder of the lanthanum doped terbium has good antibacterial property, can be used as antibacterial materials.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Powder metal explosive property'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles