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 · 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.
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
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).
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
Boron compounds
Ceramic materials
Fabrication
Machinability
Mechanical properties
Polycrystals
Zirconia
