TiC含量对无压液相烧结SiC-TiC陶瓷复合材料结构和性能的影响

Effect of TiC Content on Structure and Properties of SiC-TiC Ceramic Composites by Pressureless Liquid Phase Sintering

以SiC粉体和TiC粉体为原料,Al_(2)O_(3)-Y_(2)O_(3)为烧结助剂,采用无压液相烧结技术制备了SiC-TiC陶瓷复合材料,研究了TiC体积分数(35%~45%)对其微观结构和性能的影响。结果表明:陶瓷复合材料的物相组成均为SiC、TiC、YAG(Y_(3)Al_(2)O_(3))和YAM(Y_(4)Al_(2)O_(3));随着TiC含量的增加,TiC颗粒逐渐形成连续网络结构,陶瓷复合材料的开口气孔率先减小后增大,相对密度、抗弯强度、断裂韧度和维氏硬度均先升高后降低,体积电阻率降低。当TiC体积分数为40%时,陶瓷复合材料具有优异的综合性能,其相对密度、开口气孔率、抗弯强度、断裂韧度、维氏硬度、体积电阻率分别为98.1%,0.28%,429 MPa,5.87 MPa·m^(1/2),26GPa,1.66×10^(-5)Ω·m。

Taking SiC powder and TiC powder as raw materials,Al_(2)O_(3)-Y_(2)O_(3)as sintering aid,SiC-TiC ceramic composites were prepared by pressureless liquid phase sintering,and the effect of TiC content(35vol%-45vol%)on the microstructure and properties of the ceramic composites was studied.The results show that the phase composition of the ceramic composites was SiC,TiC,YAG(Y_(3)Al_(2)O_(3))and YAM (Y_(4)Al_(2)O_(3)).With increasing TiC content,TiC particles were formed to be a continuous network structure gradually;the open porosity of the ceramic composites decreased first and then increased,the relative density,flexural strength,fracture toughness,Vickers hardness and volume resistivity increased first and then decreased,and the volume resistivity decreased.When the TiC content was 40vol%,the ceramic composites had the excellent comprehensive properties,and the relative density,open porosity,flexural strength,fracture toughness,Vickers hardness and volume resistivity were 98.1%,0.28%,429 MPa,5.87 MPa·m^(1/2),26GPa and 1.66×10^(-5)Ω·m,respectively.