Preparation of Ti3SiC2/diamond composites by Ni-Al assisted microwave self-propagating sintering
Low carbon economy and the green economy represent the strategic direction of sustainable development.In order to reduce the manufacturing cost and energy consumption of diamond grinding tools,the preparation process of high-performance vitrified bond diamond abrasive tools,with low energy consumption was explored.The effects of the combustion promoter Si and diamond particle size on the phase composition,microstructure and grinding performance of the samples were studied.Ti3SiC2/diamond composites were prepared through self-propagating high-temperature syn-thesis(SHS)reaction of the Ti-Si-C system induced by microwave field heating with the assistance of Ni-Al.This in-volved using Ti,Si,graphite powder and diamond abrasive as raw materials.The results show that the high calorific value Ni-Al alloy can shorten the experimental time of sample sintering and control the temperature of the SHS reaction below the graphitization temperature of diamond.Ti3SiC2,TiC and Ti5Si3 phases were formed by the SHS reaction of the Ti-Si-C system in an Ar atmosphere.With an increase in Si content,the Ti3SiC2 phase increases first and then decreases.When the ratio of n(Ti)∶n(Si)∶n(C)is 3∶1.1∶2,the grinding performance of Ti3SiC2/diamond composites is op-timal,and the grinding consumption ratio of the samples can reach 286.53.The mechanism behind the difference in the grinding consumption ratio of the samples under different raw material ratios was analyzed.It is considered that the small and evenly distributed pore structure in the matrix structure can produce a large area of a flat grinding surface dur-ing grinding.This is easy to exert the grinding effect of diamond abrasives and is conducive to improving the grinding performance of composite samples.
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