Academic literature on the topic 'Melt-ceramic Nano-composites'

Composites reinforced by nano-ceramic particles typically result in the formation of clustering and a weak interface. The spatial distribution of particles and the wetting behavior remarkably affect the targeted properties. Here, a surface modification combined spatial control solution was demonstrated to prepare nanocomposites with homogeneous micro-structures. Poly-crystalline nano-MgAl2O4 particles that possess a good crystallographic orientation relationship with Al were coated on the surface of ceramic particles, and they were macro- and then microscopically dispersed in the melt by ultrasonic vibration with variable frequency. The reason this is that the acoustic pressure distributed in the Al melt can induce the acoustic streaming and cavitation. A model for calculating equilibrium particle migration velocity was proposed, based on which the distribution of particles could be controlled by adjusting the solidification rate and the size of particle clustering. The experimental results were validated by the prediction of the model. In addition, it was found that the relationship of the maximum radius angle with the contact angle was ω0=180°−θ, and ultrasonic vibration could provide enough energy for the later stage entering of particles to overcome the energy barrier.

Ceramic nanometric SiC particles (n-SiCp) were reinforced in 7075 aluminium matrix to synthesize the metal matrix nano composites (MMNCs). The inclusion as well as uniform distribution of nano particles in aluminium matrix is a great challenge. To accomplish this, a new hybrid stir casting technique was used to fabricate the MMNCs. The uniform distribution of the reinforcement depends on good wettability of reinforcement with the metal matrix. Hence, to improve the wettability, 1 wt % micro Mg particles were mechanically milled with two different additions of n-SiCp with weight fractions 1% and 1.5 % and injected into the matrix melt with the assistance of argon gas. As-casted materials were peak aged for 12 hours at 135º C. Tensile tests, low speed impact test and hardness tests were used to investigate mechanical behaviour and found that composite reinforced with 1% SiC exhibited better mechanical properties. The mechanical properties of nano-composites are characterized by employing optical microscopy, scanning electron microscopy and X-ray diffractometer. This method remarkably facilitated a uniform dispersion of nano-SiC within the aluminium matrix as well as a refinement of grain size.

In most engineering applications where fluid lubrication is practically impossible such as high temperature environment, solid lubrication becomes an alternative option. Polymers such as polytetrafluoroethylene are often used for solid lubrication due to their ability to provide low friction on interfacial sliding conditions. However, polymeric materials often show low wear resistance, which limits their applications. Therefore, there is need for high wear resistance polymers or polymer composites for such application. In this study, wear resistance of poly (vinylidene fluoride) (PVDF) was improved by incorporating hydroxylated titanium dioxide (TD-OH) and functionalized graphene nanoplatelets (fGNPs). The composites were fabricated by solution blending and further processed by melt compounding. Raman and X-ray diffractometer were used to characterize the particles, while morphological study and wear scars on the composite samples were examined using scanning electron microscope. From the results obtained, wear volume (WV) reduced from about 0.6255 mm3 for pure PVDF to 0.2439 mm3 for 3.34 wt% fGNPs composite and further reduced to 0.1473 mm3 with the addition of 10 wt% TD-OH to 3.34 wt% fGNPs composite. These are about 61% and 76% reduction respectively, compared to pure PVDF. It was noted that increase in TD-OH content up to 20 wt% in fGNPs binary composites increased the WV of the ternary composites. This indicates that ceramic nano-fillers at appropriate proportions in polymer/graphene composites can enhance the wear resistance of such composites. On the other hand, the ternary composites showed lower thermal stability compared to the binary composites, which was attributed to low thermal stability product(s) of chemical reaction between fGNPs and TD-OH in the PVDF matrix.

This study investigates the effect of dispersion of nanofiller reinforcement high performance polymer matrix to enhance the thermo-mechanical properties for bearing application. Polyetheretherketone (PEEK) matrix is reinforced with acid fucntionalized multiwalled carbon nanotubes ( f-MWCNTs) and similar matrix was then reinforced with nano tungsten carbide (nano WC) to comparatively present their mechanical, thermal and morphological properties. The Nanocomposites were prepared via melt compounding method followed by injection moulding technique. The PEEK/ f-MWCNT s nanocomposite exhibited better property enhancement than the PEEK/nano WC. Spectroscopical analysis confirmed the effectiveness of improved interfacial adhesion between PEEK and f-MWCNTs. Transmission Electron Microscope (TEM) micrograph depicted improved dispersion of f-MWCNTs in PEEK matrix than that of nano WC. Due to improved interfacial interaction between f-MWCNT s and PEEK, this resulting nanocomposite showed better mechanical, thermal and morphological properties than PEEK/nano WC. Due to ceramic nature of nano WC and higher density difference the agglomeration of particles occurred leading to lower properties.

In-situ synthesized Nb (C,N) reinforced metal-ceramic composite layers were fabricated on nitridable (16MnCr5) and non-nitridable (S235J) steel surface by combined laser melt injection technology and ferritic nitrocarburizing treatment. The feasibility of processing composites layer by an in situ reaction using laser beam were carried out. Beside that the hardness of the treated layers increases up to 1000-1170 HV0.5 in the diffusion zone and after it the hardness of the samples reach 300-450 HV0.5, which is related the Nb alloying depth (1200-1400 μm). The results of the composite layer are presented in this paper.

The automotive design process and the materials in the automotive industry in recent years has caused great interest to the industrial and academic sector. In this study was to evaluate the effect of the amount of bentonite on the thermal and rheological properties of the compound bentonite / paraffin wax. Two bentonite ratios were used: paraffin wax (40:60 and 30:70). The paraffin was characterized by Fourier transform infrared spectroscopy (FTIR), the bentonite was characterized by means of x-ray diffraction (XRD), thermogravimetric analysis (TGA), X-ray fluorescence (XRF). The bentonite/paraffine wax composite was characterized by differential-scanning calorimetry (DSC) and rheology. The sample that contains a higher amount of bentonite shows a lower latent heat, and this could cause a greater heat transfer. Finally, the sample that has a lower amount of bentonite evidenced a lower viscosity, and it could be related to a lower interaction between the particles. The sample S1 due to its lower latent heat compared to S2 could represent an interesting alternative to develop prototypingclays. since these materials are characterized by their low working temperatures and easy malleability. Keywords: automotive, prototyping, latent heat, bentonite, paraffin. References [1]X. Ferràs-Hernández, E. Tarrats-Pons, and N. Arimany-Serrat, “Disruption in the automotive industry: A Cambrian moment,” Bus. Horiz., vol. 60, no. 6, pp.855–863, 2017, doi: 10.1016/j.bushor.2017.07.011. [2]O. Heneric, G. Licht, S. Lutz, and W. Urban, “The Europerean Automotive Industry in a Global Context,” Eur. Automot. Ind. Move, pp. 5–44, 2005, doi: 10.1007/3-7908-1644-2_2. [3]S. I.-N. Delhi, “Automotive Revolution & Perspective Towards 2030,” Auto Tech Rev., vol. 5, no. 4, pp. 20–25, Apr. 2016, doi: 10.1365/s40112-016-1117-8.[4]M. Tovey, J. Owen, and P. Street, “in Automotive Design,” vol. 21, pp. 569–588, 2000. [5]Yasusato Yamada, Clay modeling : techniques for giving three-dimensional form to idea. 1997. [6]H. Murray, “Industrial clays case study,” Mining, Miner. Sustain. Dev., vol. 1, no. 64, pp. 1–9, 2002, [Online]. Available: http://www.whitemudresources.com/public/Hayn Murray Clays Case Study.pdf%0Ahttp://whitemudresources.com/public/Hayn Murray ClaysCase Study.pdf. [7]Transparency Market Research, “Industrial Clay Market - Global Industry Analysis, Size, Share, Growth, Trends, and Forecast 2016 - 2024,” New york, 2016.[8]J. Murphy, Additives for Plastics Handbook. Elsevier, 2001. [9]Y. Hong, J. J. Cooper-White, M. E. Mackay, C. J. Hawker, E. Malmström, and N. Rehnberg, “A novel processing aid for polymer extrusion: Rheology and processing of polyethylene and hyperbranched polymer blends,” J. Rheol. (N. Y. N. Y)., vol. 43, no. 3, pp. 781–793, 1999, doi: 10.1122/1.550999. [10]D. P. Rawski, P. Edwards, and U. States, “Pulp and Paper : Non fi brous Components,” no. January, pp.1–4, 2017, doi: 10.1016/B978-0-12-803581-8.10289-9. [11]J. Speight, “Instability and incompatibility of tight oil and shale oil,” Shale Oil Gas Prod. Process., pp. 915–942, 2020, doi: 10.1016/b978-0-12-813315-6.00017-8. [12]T. P. Brown, L. Rushton, M. A. Mugglestone, and D. F. Meechan, “Health effects of a sulphur dioxide air pollution episode,” vol. 25, no. 4, pp. 369–371, 2003,doi: 10.1093/pubmed/fdg083. [13]R. Chihi, I. Blidi, M. Trabelsi-Ayadi, and F. Ayari, “Elaboration and characterization of a low-cost porous ceramic support from natural Tunisian bentonite clay,” Comptes Rendus Chim., vol. 22, no. 2–3, pp. 188–197, 2019, doi: 10.1016/j.crci.2018.12.002. [14]Z. Yi, W. Xiaopeng, and L. I. Dongxu, “Prepartion of organophilic bentonite / paraffin composite phase change energy storage material with melting intercalation method,” pp. 126–131, 2011, doi: 10.4028/www.scientific.net/AMR.284-286.126. [15]I. Krupa and A. S. Luyt, “Thermal and mechanical properties of extruded LLDPE / wax blends,” vol. 73, pp. 157–161, 2001. [16]A. Saleem, L. Frormann, J. Koltermann, and C. Reichelt, “Fabrication and Processing of Polypropylene - Paraffin Compounds with Enhanced Thermal andProcessing Properties : Impact Penetration and Thermal Characterization,” vol. 40164, pp. 1–9, 2014, doi:10.1002/app.40164. [17]M. Mu, P. A. M. Basheer, W. Sha, Y. Bai, and T. Mcnally, “Shape stabilised phase change materials based on a high melt viscosity HDPE and paraffin waxes,”Appl. Energy, vol. 162, pp. 68–82, 2016, doi: 10.1016/j.apenergy.2015.10.030. [18]M. Tovey, “Intuitive and objective processes in automotive design,” Des. Stud., vol. 13, no. 1, pp. 23–41, 1992, doi: 10.1016/0142-694X(92)80003-H. [19]J. Verlinden, A. Kooijman, E. Edelenbos, and C. Go, “Investigation on the use of illuminated clay in automotive styling,” 6th Int. Conf. Comput. Ind. Des.Concept. Des. (CAID&CD), Delft, NETHERLANDS, pp. 514–519, 2005. [20]N. W. Muhamad Bustaman and M. S. Abu Mansor, “A Study on CAD/CAM Application in CNC Milling Using Industrial Clay,” Appl. Mech. Mater., vol. 761, pp. 32–36, 2015, doi: 10.4028/www.scientific.net/AMM.761.32. [21]K. Shimokawa, Japan and the global automotive industry. 2010. [22]A. Bucio, R. Moreno tovar, L. Bucio, J. Espinosadávila, and F. Anguebes franceschi, “Characterization of beeswax, candelilla wax and paraffin wax for coatingcheeses,” Coatings, vol. 11, no. 3, pp. 1–18, 2021, doi: 10.3390/coatings11030261. [23]F. Valentini, A. Dorigato, A. Pegoretti, M. Tomasi, G. D. Sorarù, and M. Biesuz, “Si3N4 nanofelts/paraffin composites as novel thermal energy storage architecture,” J. Mater. Sci., vol. 56, no. 2, pp. 1537–1550, 2021, doi: 10.1007/s10853-020-05247-5. [24]F. Paquin, J. Rivnay, A. Salleo, N. Stingelin, and C. Silva, “Multi-phase semicrystalline microstructures drive exciton dissociation in neat plastic semiconductors,” J. Mater. Chem. C, vol. 3, pp. 10715–10722, 2015, doi: 10.1039/b000000x. [25]R. S. Hebbar, A. M. Isloor, B. Prabhu, Inamuddin, A. M. Asiri, and A. F. Ismail, “Removal of metal ions and humic acids through polyetherimide membranewith grafted bentonite clay,” Sci. Rep., vol. 8, no. 1, 2018, doi: 10.1038/s41598-018-22837-1. [26]S. Betancourt-Parra, M. A. Domínguez-Ortiz, and M. Martínez-Tejada, “Colombian clays binary mixtures: Physical changes due to thermal treatments,” DYNA, vol. 87, no. 212, pp. 73–79, 2020, doi: 10.15446/dyna.v87n212.82285. [27]A. M. Rabie, E. A. Mohammed, and N. A. Negm, “Feasibility of modified bentonite as acidic heterogeneous catalyst in low temperature catalytic crackingprocess of biofuel production from nonedible vegetable oils,” J. Mol. Liq., vol. 254, no. 2018, pp. 260–266, 2018, doi: 10.1016/j.molliq.2018.01.110. [28]A. Kadeche et al., “Preparation, characterization and application of Fe-pillared bentonite to the removal of Coomassie blue dye from aqueous solutions,” Res. Chem. Intermed., vol. 46, no. 11, pp. 4985–5008, 2020, doi: 10.1007/s11164-020-04236-2. [29]C. I. R. De Oliveira, M. C. G. Rocha, A. L. N. DaSilva, and L. C. Bertolino, “Characterization of bentonite clays from Cubati, Paraíba Northeast of Brazil,” Ceramica, vol. 62, no. 363, pp. 272–277, 2016, doi:10.1590/0366-69132016623631970. [30]I. Z. Hager, Y. S. Rammah, H. A. Othman, E. M. Ibrahim, S. F. Hassan, and F. H. Sallam, “Nano-structured natural bentonite clay coated by polyvinyl alcohol polymer for gamma rays attenuation,” J. Theor. Appl. Phys., vol. 13, no. 2, pp. 141–153, 2019, doi: 10.1007/ s40094-019-0332-5. [31]A. Tebeje, Z. Worku, T. T. I. Nkambule, and J. Fito, “Adsorption of chemical oxygen demand from textile industrial wastewater through locally prepared bentonite adsorbent,” Int. J. Environ. Sci. Technol., no. 0123456789, 2021, doi: 10.1007/s13762-021-03230-4. [32]F. E. Özgüven, A. D. Pekdemir, M. Önal, and Y. Sarıkaya, “Characterization of a bentonite and its permanent aqueous suspension,” J. Turkish Chem. Soc.Sect. A Chem., vol. 7, no. 1, pp. 11–18, 2019, doi: 10.18596/jotcsa.535937. [33]S. Tao, S. Wei, and Y. Yulan, “Characterization of Expanded Graphite Microstructure and Fabrication of Composite Phase-Change Material for Energy Storage,” J. Mater. Civ. Eng., vol. 27, no. 4, p. 04014156, 2015, doi: 10.1061/(asce)mt.1943-5533.0001089. [34]M. Li, Z. Wu, H. Kao, and J. Tan, “Experimental investigation of preparation and thermal performances of paraffin/bentonite composite phase change material,” Energy Convers. Manag., vol. 52, no. 11, pp. 3275–3281, 2011, doi: 10.1016/j.enconman.2011.05.015. [35]S. M. Hosseini, E. Ghasemi, A. Fazlali, and D. E. Henneke, “The effect of nanoparticle concentration on the rheological properties of paraffin-based Co3O4 ferrofluids,” J. Nanoparticle Res., vol. 14, no. 7, 2012, doi: 10.1007/s11051-012-0858-9.

In this thesis, a novel in-situ method for incorporating nanoscale ceramic particles into metal has been developed. The ceramic phase is introduced as an organic-polymer precursor that pyrolyzes in-situ to produce a ceramic phase within the metal melt. The environment used to shield the melt from burning also protects the organic precursor from oxidation. The evolution of volatiles (predominantly hydrogen) as well as the mechanical stirring causes the polymer particles to fragment into nanoscale dispersions of a ceramic phase. These “Polymer-based In-situ Process-Metal Matrix Composites” (PIP-MMCs) are likely to have great generality, because many different kinds of organic precursors are commercially available, for producing oxides, carbides, nitrides, and borides. Also, the process would permit the addition of large volume fractions of a ceramic phase, enabling nanostructural design, and production of MMCs with a wide range of mechanical properties, meant especially for high temperature applications. An important and noteworthy feature of the present process, which distinguishes it from other methods, is that all the constituents of the ceramic phase are built into the organic molecules of the precursor (e.g., polysilazanes contain silicon, carbon, and nitrogen); therefore, a reaction between the polymer and the host metal is not required to produce the dispersion of the refractory phase. The polymer precursor powder, with a mean particle size of 31.5 µm, was added equivalent to 5 and 10 weight % of the melt (pure magnesium) by a liquid metal stir-casting technique. SEM and OM microstructural observations show that in the cast structure the pyrolysis products are present in the dendrite boundary region in the form of rod/platelets having a thickness of 100 to 200 nm. After extrusion the particles are broken down into fine particles, having a size that is comparable to the thickness of the platelets, in the 100 to 200 nm range, and are distributed more uniformly. In addition, limited TEM studies revealed the formation of even finer particles of 10-50 nm. X-ray diffraction analysis shows the presence of a small quantity of an intermetallic phase (Mg2Si) in the matrix, which is unintended in this process. There was a significant improvement in mechanical properties of the PIP-MMCs compared to the pure Mg. These composites showed higher macro-and micro-hardness. The composite exhibited better compressive strength at both room temperature and at elevated temperatures. The increase in the density of PIP-composites is less than 1% of Mg. Five weight percent of the precursor produced a two-fold increase in the room-temperature yield strength and reduced the steady state creep rate at 723 K by one to two orders of magnitude. PIP-MMCs showed higher damping capacity and modulus compared to pure Mg, with the damping capacity increasing by about 1.6 times and the dynamic modulus by 11%-16%. PIP-composites showed an increase in the sliding wear resistance by more than 25% compared to pure Mg.

In this thesis, a novel in-situ method for incorporating nanoscale ceramic particles into metal has been developed. The ceramic phase is introduced as an organic-polymer precursor that pyrolyzes in-situ to produce a ceramic phase within the metal melt. The environment used to shield the melt from burning also protects the organic precursor from oxidation. The evolution of volatiles (predominantly hydrogen) as well as the mechanical stirring causes the polymer particles to fragment into nanoscale dispersions of a ceramic phase. These “Polymer-based In-situ Process-Metal Matrix Composites” (PIP-MMCs) are likely to have great generality, because many different kinds of organic precursors are commercially available, for producing oxides, carbides, nitrides, and borides. Also, the process would permit the addition of large volume fractions of a ceramic phase, enabling nanostructural design, and production of MMCs with a wide range of mechanical properties, meant especially for high temperature applications. An important and noteworthy feature of the present process, which distinguishes it from other methods, is that all the constituents of the ceramic phase are built into the organic molecules of the precursor (e.g., polysilazanes contain silicon, carbon, and nitrogen); therefore, a reaction between the polymer and the host metal is not required to produce the dispersion of the refractory phase. The polymer precursor powder, with a mean particle size of 31.5 µm, was added equivalent to 5 and 10 weight % of the melt (pure magnesium) by a liquid metal stir-casting technique. SEM and OM microstructural observations show that in the cast structure the pyrolysis products are present in the dendrite boundary region in the form of rod/platelets having a thickness of 100 to 200 nm. After extrusion the particles are broken down into fine particles, having a size that is comparable to the thickness of the platelets, in the 100 to 200 nm range, and are distributed more uniformly. In addition, limited TEM studies revealed the formation of even finer particles of 10-50 nm. X-ray diffraction analysis shows the presence of a small quantity of an intermetallic phase (Mg2Si) in the matrix, which is unintended in this process. There was a significant improvement in mechanical properties of the PIP-MMCs compared to the pure Mg. These composites showed higher macro-and micro-hardness. The composite exhibited better compressive strength at both room temperature and at elevated temperatures. The increase in the density of PIP-composites is less than 1% of Mg. Five weight percent of the precursor produced a two-fold increase in the room-temperature yield strength and reduced the steady state creep rate at 723 K by one to two orders of magnitude. PIP-MMCs showed higher damping capacity and modulus compared to pure Mg, with the damping capacity increasing by about 1.6 times and the dynamic modulus by 11%-16%. PIP-composites showed an increase in the sliding wear resistance by more than 25% compared to pure Mg.

Novel metal oxide-doped fluorophosphates nano-glass powders were synthesized by melt quenching method, and their non-toxicity is proved by MTT. Their efficacy in bone formation is confirmed by osteocalcin and ALP secretion. Composites were made using PLA, PDLLA, PPF, or 1,2-diol with fluorophosphates nano-glass powders (AgFp/MgFp/ZnFp). Their non-toxicity was assessed by cell adhesion and MTT. The ability of the composite for bioconversion was assessed by RT-PCR estimation for osteocalcin, Collagen II, RUNX2, Chondroitin sulfate, and ALP secretion accessed by ELISA method. The animal study in rabbit showed good callus formation by bioconduction and bioinduction. The bioconversion of the composite itself was proved by modified Tetrachrome staining. From the 12 different composites with different composition, the composite PPF+PDLLA+PPF+ZnFp showed the best results. These obtained results of the composites made from common biological molecules are better than the standards and so they do biomimic as bone substitutes. The composites can be made as strips or granules or cylinders and will be a boon to the operating surgeon. The composite meets nearly all the requirements for bone tissue engineering and nullifies the defect in the existing ceramic composites.

Abstract The high velocity oxy-fuel (HVOF) combustion spray process has previously been shown to be a successful method for depositing pure polymer and polymer/ceramic composite coatings. Polymer and polymer-ceramic composite particles have high melt viscosities and require the high kinetic energy of HVOF in order to generate sufficient particle flow and deformation on impact. One of the goals of reinforcing polymer coatings with particulate ceramics is to improve their durability and wear performance. Composite coatings were produced by ball-milling 60 µm Nylon-11 together with nominal 10 vol.% of nano and multi-scale ceramic reinforcements and HVOF spraying these composite feedstocks onto steel substrates to produce semi-crystalline micron and nano-scale reinforced coatings of polymer matrix composites. The room temperature dry sliding wear performance of pure Nylon-11, Nylon-11 reinforced with 7 nm silica, and multi-scale Nylon-11/silica composite coatings incorporating 7 to 40 nm and 10 µm ceramic particles was determined and compared. Coatings were sprayed onto steel substrates, and their sliding wear performance determined using a pin-on-disk tribometer. Coefficient of friction was recorded and wear rate determined as a function of applied load and coating composition. Surface profilometry and scanning electron microscopy were used to characterize and analyze the coatings and wear scars.

Abstract A significant challenge within the manufacturing of Ceramic Matrix Composites (CMCs) is the creation of the fibre-matrix interphase which enables the damage tolerant behavior of CMCs. Chemical vapour deposition (CVD) has been a highly successful approach for fabricating fibre-matrix interphases; however, CVD requires capital intensive facilities and hazardous precursors. This work examines electrophoretic deposition (EPD) as an alternative route for the production of fibre-matrix interphases. Four multilayered fibre-matrix interphases (SiC/Al2O3, BN/ZrO2, ZrC/85wt%Al2O3-15wt%ZrO2, and SiC/Si3N4/SiC) were produced through multi-staged electrophoretic deposition of ceramic nano-powders upon SiC fibre bundles. A 25-2 factorial design of experiments is utilized to explore the effect of different levels of the following variables: electric field strength, duration, surfactant, solids loading and binder. Following deposition of the fibre-matrix interphase the fibre bundles are thinly coated with a SiC matrix through a reactive melt infiltration technique. The resultant microcomposites are then subjected to tensile loading until failure to determine which coating and deposition combination are the most likely to yield favorable tensile properties. Additional microscopy is performed to determine the uniformity and thickness of the coatings. The results are then examined to evaluate the suitability of electrophoretic deposition as a production technique for fibre-matrix interphase coatings in CMCs.