Papers by Keyword: SiC

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Authors: Kerim Emre Öksüz
Abstract: Increasing density is the best way to increase the performance of powder metallurgy materials. Conventional powder metallurgy processing can produce copper green compacts with density less than 8.3g/cm3 (a relative density of 93%). Warm compaction, which is a simple and economical forming process to prepare high density powder metallurgy parts or materials. CuSn matrix composites with %2 weight fractions of reinforcement particles were prepared using warm compaction and sintering. Micro-structural aspects were observed by optical microscope. Density, hardness and wear tests were also performed. Abrasion resistance measurements were used to study the abrasive behaviors of CuSn matrix and its composites. The effects of reinforcement and preparation methods on the microstructure and mechanical properties of composites have been investigated.
Authors: S. Nallusamy
Abstract: In the present investigation, properties of the Friction Stir Welded (FSW) Aluminium 6351 alloy plates added with SiC particles in the weld zone was studied. The qualities of welds were determined in two conditions of as-weld condition and annealed condition. In addition, the hardening parameters were calculated to evaluate the quality of friction stir welds of Al 6351 alloy plates. Using swift hardening law, strength coefficient (k) and strain (ε) values were calculated keeping hardening exponent (n) as constant for Al 6351 alloy. The calculated values of strength coefficient and strain were found to be present within the theoretical design limits for both as-weld and annealed conditions. Thus the process ensures the quality of friction stir welded joints of Al 6351 alloy plates with SiC particles in the weld region both in theoretical and experimental aspects.
Authors: Feng Zhang, Guang Hai Wang, Yu Feng Chen, Chuan Qi Hu, Hao Ran Sun, Shi Chao Zhang, Xian Kai Sun, Kai Fang
Abstract: Modified phenolic resin-based adhesive is used as the high temperature binder, which is prepared by adding different additives, zirconium diboride, boron carbide as modified fillers, and H3PO4, AlPO4 as curing agents. The influence of additives for phenolic resin-based adhesive on bond property of SiC ceramic was studied after heat treatment at 400 oC , 800 oC , 1200 oC , 1600 oC. The results show that the improvement of adhesion property for curing agents is not obvious. B4C modified phenolic resin-based adhesive exhibits better adhesion performance than ZrB2 modified phenolic resin-based adhesive. Bonding property of B4C modified phenolic resin-based adhesive is best at 1200 oC , and the adhesive strength is reduced above 1200 oC along with rising of the heat treatment temperature. Because of the formation of shrinkage micro-defects of phenolic resin, bond strength exists a sharp decline after 1200 oC heat treatment.
Authors: Mihail Ionescu, Alec Deslandes, Rohan Holmes, Mathew C. Guenette, Inna Karatchevtseva, Gregory R. Lumpkin
Abstract: Silicon carbide (3C-β SiC) samples were irradiated with He ions of energy up to 30 keV and a fluence up to 1016/cm2, to produce damage in the near-surface region. A duplicate set of He ion irradiated SiC samples, as well as undamaged SiC, were also irradiated with H2+ ions of energy up to 20 keV and a similar fluence, to study the interaction of H species with pristine SiC and with He radiation-damaged SiC. Samples were annealed in steps of 200 K, from 473 K to 1273 K, and the retention of H and He were measured using elastic recoil detection analysis with 7.8 MeV C3+ ions, after each anneal step. Modification to the surface following irradiation is observed via Raman spectroscopy, which exhibits development of damage states such as disordered carbon and Si-Si peaks. Only minor changes in the H and He profiles were observed up to 1073 K, however after the 1273 K anneal the H and He profiles changed considerably, with a marked difference between samples irradiated only with He and those irradiated with He and H.
Authors: Hülya Akkan, Mehmet Şi̇mşi̇r, Kerim Emre Öksüz
Abstract: NiTi shape memory alloys have attracted significant interest due to their unique superelasticity and high damping performance. In this work, the effect of SiC particle size on both physical and mechanical properties of NiTi matrix composite was investigated. Ni and Ti powders with particle sizes of 40 µm were used with the SiC addition with varying particle sizes of 20 µm and 40 µm, respectively. Composites of NiTi with 1wt. % SiC were fabricated by powder metallurgy technique. The effects of SiCp addition on hardness, relative density and wear behavior of NiTi composites have been investigated. The samples were examined by scanning electron microscope, for microstructural studies and phase development. The results showed that the distribution of the reinforced particle was uniform. Moreover, as the SiC particle size decreases, hardness and wear resistance increase. It was demonstrated that SiC particle size significantly enhanced the wear resistance of NiTi composite.
Authors: Soon Ki Jeong
Abstract: Electrochemical reactions occurring at a SiC electrode were investigated to gain insight into the effects of lithium salts, such as LiPF6, LiClO4, LiCF3SO3, and LiBF4, on the interfacial resistance. Lithium salts were found to exert little effect on the magnitude of the resistance of the solid-electrolyte interphase (SEI). In contrast, the charge-transfer reactions observed in the LiCF3SO3-containing solution exhibited the smallest resistance. Charge-discharge analysis revealed that the nature of the SEI was significantly different from that formed in ethylene carbonate-based solutions containing different lithium salts. The SiC electrode exhibited large discharge capacity and low coulombic efficiency in the LiCF3SO3-containing solution. This might be closely related to the smallest charge-transfer resistance.
Authors: Najwa binti Hamzan, Muhammad Firdaus Omar, Huang Nay Ming, Boon Tong Goh
Abstract: Well-aligned NiSi/SiC core-shell nanowires were grown on Ni-coated p-type crystal Si (100) substrates by using hot-wires chemical vapor deposition (HWCVD) technique. The growth of the nanowires was performed at a substrate temperature of 450°C and facilitated by a hot-filament at a temperature above 1800°C. Electron microscopy characterizations were employed to investigate the morphology, and microstructure properties of the nanowires. A high-resolution transmission electron microscopy (TEM) images indicate that the nanowires were structured by single crystalline NiSi and amorphous SiC as the core and shell respectively. Moreover, the TEM images showed presence of 3C-SiC nano-crystallites embedded within an amorphous matrix in the shell.
Authors: A. Karthikeyan, S. Nallusamy
Abstract: One of the most common problems encountered in many industrial products and its applications is wear. The purpose of this experimental research article is to analyze the wear behaviour of Al-6063 based SiC composites using pin on disc testing machine. In this present investigation there are nine different samples of Al/SiC composites with 5%, 7% and 9% volume of SiC were prepared through stir casting process. The sliding distance of 500 meter and the load 10 N were applied for wear testing of these prepared samples. From the experimental results, it was observed that the sliding velocity is greatly affects the wear rate and on increasing the sliding velocity the wear loss increases. It was also found that the wear loss decreases by increasing the amount of reinforcement element. Scanning electron microscope was used to examine the wear surfaces and found that the micro and transverse cracks, mild and severe wear occurred in the composite worn surfaces and wear structure of the composites.
Authors: Penchal Reddy Matli, Ubaid Fareeha, Rana Abdul Shakoor, Moinuddin Yusuf, Adel Mohamed Amer Mohamed, Manoj Gupta
Abstract: This work aims to investigate the effect of SiC addition on structural, microstructural and mechanical properties of developed Al-Sic nanocomposites. Al metal matrix composites reinforced by nanosized SiC particles were fabricated using high energy ball milling and microwave sintering process followed by hot extrusion. The XRD analysis indicated that the dominant components were Al and SiC. SEM/EDX micrographs showed homogenous distribution of SiC nanoparticles in Al matrix. Mechanical characterizations revealed that the addition of nanosize SiC particulates to a simultaneous increase in microhardnes, yield strength, ultimate compressive/tensile strength and reduction in ductility of the matrix. This improvement in mechanical properties can be attributed to the homogeneous distribution of reinforcement (SiC particles) and dispersion strengthening mechanism.
Authors: Gurpreet Singh Saini, Sanjeev Goyal
Abstract: In the present paper aluminum matrix composites were fabricated using base material AA6082-T6. SiC and B4C particulates were used as reinforcement to obtain hybrid and non-hybrid composites through the conventional stir casting process. AA6082-T6/SiC composites with 5, 10, 15 and 20 wt % of SiC; AA6082-T6/B4C composites with 5, 10, 15 and 20 wt % of B4C and AA6082-T6/(SiC+B4C) hybrid composites with 5, 10, 15 and 20 wt % of (SiC+B4C) taking equal fraction of SiC and B4C were made and the microstructure study was carried out. X-Ray diffraction (XRD) patterns revels the presence of reinforcement within the matrix along with some other compounds. The microstructure of the fabricated composites was examined with the help of Scanning electron microscope (SEM) and the micrographs revealed that the dispersion of reinforced particles was reasonably uniform at all weight percentages.
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