摘要
以Si3N4和BN粉末为原料,Si3N4-BN复合粉末中BN的体积分数分别选定为10%、20%和30%,采用质量分数为2%的Al2O3和6%的Y2O3作为烧结助剂,分别在1500、1600和1650℃,压力50 MPa,保温5 min的条件下,采用放电等离子体烧结法制备了致密Si3N4-BN复合陶瓷。XRD结果和SEM分析表明:当煅烧温度为1650℃时,复合陶瓷中的α-Si3N4已完全转变为β-Si3N4;BN的加入抑制了复合陶瓷中Si3N4晶粒的生长而使结构细化;复合陶瓷的维氏硬度和断裂韧性随BN含量的增加而逐渐降低。
Dense Si3N4-BN composite ceramics were fabricated by spark plasma sintering at 1 500,1 600 and 1 650 ℃ under 50 MPa for 5 min using Si3N4 and BN powders as starting materials and 2 wt% Al2O3 and 6 wt% Y2O3 as sintering additives.The volume fraction of BN in Si3N4-BN composite powders was chosen as 10%,20%,and 30%,respectively.The results of XRD and SEM show that α-Si3N4 completely turns into β-Si3N4 when the composite ceramics are sintered at 1 650 ℃;the addition of BN hinders the growth of Si3N4 grains,refining the structure;Vickers hardness and fracture toughness of the composite ceramics decrease with the increase of BN content.
出处
《耐火材料》
CAS
北大核心
2010年第6期426-429,共4页
Refractories
基金
国家自然科学基金项目(50374007)
