α-Al2 O3微粉对 Al2 O3－Ti3 SiC2复合材料常温导电性能的影响

摘要

The Al 2 O3-Ti 3 SiC2 composites were prepared using Ti powder,Si powder and TiC powder with the mass ratio of 1∶1.2∶2,extra adding different additions of α-Al 2 O3 micropowder with various particles si-zes,and then hot pressing sintering.Effects of hot treatment temperatures (1 300,1 350,1 400,1 450,1 500, and 1 550 ℃),additions (10%,20%,30%,40%,and 50%,by mass)and particle sizes (50 nm,500 nm, 800 nm,and 7 μm)of α-Al 2 O3 micropowders on phase composition,microstructure,room temperature electric conductivity of the composites were researched.The results show that:the phase composition of the composites is mainly Ti 3 SiC2 ,TiC,and corundum;the suitable hot pressing sintering temperature is 1 450 ℃;with α-Al 2 O3 micropowder addition increasing and nano particle size enlarging,the electric con-ductivity of the composites decreases.Micron α-Al 2 O3 powder is more beneficial to electric conductivity than nano α-Al 2 O3 powder.%为研究 Ti3 SiC2材料的导电性能，将 Ti 粉、Si 粉、TiC 粉按物质的量比为11．22混合，外加不同含量和不同粒度的α-Al2 O3微粉经热压烧结制备了 Al2 O3－Ti3 SiC2复合材料。研究了热压烧结温度（1300、1350、1400、1450、1500和1550℃）、α-Al2 O3微粉的添加量（质量分数分别为10％、20％、30％、40％和50％）及粒径（50 nm、500 nm、800 nm 和7μm）对该复合材料的物相组成、显微结构、常温导电性能等的影响。结果表明：热压烧结制备的 Al2 O3－Ti3 SiC2复合材料的物相主要有 Ti3 SiC2、TiC 和刚玉，合适的热压烧结温度为1450℃；随着α-Al2 O3微粉含量和纳米级粒径的增大，Al2 O3－Ti3 SiC2复合材料的导电性能呈线性下降趋势，微米级比纳米级更有益于材料的导电性。