TZP-BN-10%Si_3N_4可加工复合材料的制备及其性能研究  

Fabrication and Properties of Machinable TZP-BN-10%Si_3N_4 Ceramic Composites

作　　者：李永利[1] 乔冠军[1] 金志浩[1] 

机构地区：[1]西安交通大学金属材料强度国家重点实验室,西安710049

出　　处：《西安交通大学学报》2003年第5期508-511,共4页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(50072017).

摘　　要：利用热压烧结制备出TZP(四方氧化锆多晶体) BN 10%Si3N4复合材料,BN的体积分数分别为0,5%,10%,15%,20%,30%,40%.当BN的体积分数不小于15%时,复合材料可用硬质合金钻头钻孔.在固定轴向压力下,钻孔速率随BN含量呈线性增长,同时,抗弯强度与断裂韧性则随BN含量的增加而下降,当BN的体积分数小于20%时下降缓慢,当BN的体积分数大于20%时下降迅速.当BN的体积分数等于20%时,复合材料具有最佳的综合性能:抗弯强度为637MPa,断裂韧性为9 22MPa·m1/2,钻孔速率大于2mm/min.TZP-BN-10% Si3N4 ceramic composites, whose volume fraction is 0,5%, 10%, 15% ,20% ,30% and 40%, respectively, were fabricated by hot-pressing the powder mixture of TZP (zirconia tetragonal polycrystal), h-BN and 10% mass fraction of Si3N4. It is found that the composites with BN volume fraction over 15% have a good machinability, namely, the composites can be machined by WC metal tools. Vickers hardness of the composites decreases with h-BN content. With the increase of the BN volume fraction, both bending strength and fracture toughness of the composites show a slow decrease when BN volume fraction is less than 20% and a steep decrease when BN volume fraction is over 20%. The composite possesses the combination of high mechanical properties and excellent machinability when BN volume fraction equals 20%-the bending strength is 637 MPa, the fracture toughness is 9.22 MPa &middot m1/2, and the drilling rate is more than 2 mm/min. Drilling rates and normal forces are used to evaluate the machinability of these materials.

关 键 词：复合材料 四方氧化锆多晶体 氮化硼 力学性能 可加工性 

分 类 号：TQ174[化学工程—陶瓷工业]