AI 5083//10 wt% SiCp nano composites have been synthesized by means of high energy ball milling followed by spark plasma sintering （SPS）. Nano composites produced via this method exhibited near-theoretical density w...AI 5083//10 wt% SiCp nano composites have been synthesized by means of high energy ball milling followed by spark plasma sintering （SPS）. Nano composites produced via this method exhibited near-theoretical density while retaining the nano-grained features. X-ray diffraction （XRD） analysis indicated that the crystalline size of the ball milled AI 5083 matrix was observed to be～25 nm and it was coarsened up to～30 nm after SPS. Nano indentation results of nano composites demonstrated a high hardness of～280 HV with an elastic modulus of 126 GPa. Wear and friction characteristics with addition of SiCp reinforcement exhibited significant improvement in terms of coefficient of friction and specific wear rate to that of nano structured AI 5083 alloy. The reduction in specific wear rate in the nanocomposite was mainly due to the change of wear mechanism from adhesive to abrasive wear with the addition of SiCp which resulted in high hardness associated with nano-grained microstructure.展开更多
Synthesis of silicon carbide has been carried out using thermal plasma processing technique using SiO2 as the solid feed and CH4 as the gaseous reducing agent. Thermochemical calculations have been performed varying t...Synthesis of silicon carbide has been carried out using thermal plasma processing technique using SiO2 as the solid feed and CH4 as the gaseous reducing agent. Thermochemical calculations have been performed varying the molar ratio of silicon dioxide and methane to determine the feasibility of the reaction. Experiments using a molar ratio of SiO2：CH4 equal to 1：2 produced maximum yield of SiC of about 65 mol % at a solid feed rate of 5 g/min. Mostly spherical morphology with some nanorods has been observed. The presence of Si had been observed and was quantified using XRD, HRTEM, Raman spectroscopy and X-ray photoelectron microscopy （XPS）. Si acts as a nucleating agent for SiC nanorods to grow.展开更多
基金supported by Council of Scientific and Industrial Research(CSIR)under its network project(CSIR-NWP-51)entitled"Nanostructured Advanced Materials(NAM)"
文摘AI 5083//10 wt% SiCp nano composites have been synthesized by means of high energy ball milling followed by spark plasma sintering （SPS）. Nano composites produced via this method exhibited near-theoretical density while retaining the nano-grained features. X-ray diffraction （XRD） analysis indicated that the crystalline size of the ball milled AI 5083 matrix was observed to be～25 nm and it was coarsened up to～30 nm after SPS. Nano indentation results of nano composites demonstrated a high hardness of～280 HV with an elastic modulus of 126 GPa. Wear and friction characteristics with addition of SiCp reinforcement exhibited significant improvement in terms of coefficient of friction and specific wear rate to that of nano structured AI 5083 alloy. The reduction in specific wear rate in the nanocomposite was mainly due to the change of wear mechanism from adhesive to abrasive wear with the addition of SiCp which resulted in high hardness associated with nano-grained microstructure.
文摘Synthesis of silicon carbide has been carried out using thermal plasma processing technique using SiO2 as the solid feed and CH4 as the gaseous reducing agent. Thermochemical calculations have been performed varying the molar ratio of silicon dioxide and methane to determine the feasibility of the reaction. Experiments using a molar ratio of SiO2：CH4 equal to 1：2 produced maximum yield of SiC of about 65 mol % at a solid feed rate of 5 g/min. Mostly spherical morphology with some nanorods has been observed. The presence of Si had been observed and was quantified using XRD, HRTEM, Raman spectroscopy and X-ray photoelectron microscopy （XPS）. Si acts as a nucleating agent for SiC nanorods to grow.
