Microstructure and mechanical properties of TiC whisker toughened Si3N4 based composite ceramic
Si3N4-TiCw composite ceramic materials were prepared by hot press sintering technology using α-Si3N4 as matrix,TiC whisker(TiCw for short)as toughened phase,Al2O3,Y2O3 and TiO2 as sintering additives.The effects of TiC whisker content on microstructure and mechanical properties of the Si3N4-TiCw composite ceramic materials were analyzed.The results show that the α-Si3N4 phase is partially transformed into β-Si3N4 phase during the sintering.When the content of TiCw is less than 30 vol%,it is uniformly distributed in the Si3N4 matrix,which has good chemical compatibility with Si3N4.The appropriate addition amount of TiCw can reduce the surface diffusion between Si3N4 particles and inhibit the abnormal growth of Si3N4 grains,thereby increasing the density of the composite ceramic materials.When the content of TiCw is 30 vol%,the Si3N4-TiCw composite ceramic material has the best performance,with the density of 97.71%,the flexural strength of 720.463 MPa,the fracture toughness of 7.6 MPa·m1/2,and the Vickers hardness of 18.412 GPa.
Si3N4 based ceramicTiC whiskermicrostructuremechanical property
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