摘要
以BN粉、Si粉、SiC粉、Ti-Si-Fe合金、助烧剂B_(2)O_(3)及外加结合剂酚醛树脂(PFF)为原料,采用原位氮化反应烧结制备BN/SiC/Si_(3)N_(4)复相陶瓷材料。探讨了在氮气气氛中添加不同含量Ti-Si-Fe合金部分替代硅粉及不同的气压下制得试样的力学性能差异。结果表明,Ti-Si-Fe合金中的Fe、Mn等元素促进了硅粉的氮化和氮化硅晶须的生长,所有的氮化产物均可以更好地填充气孔并提高试样的致密化程度以及调控材料的力学性能。当Ti-Si-Fe合金添加量为1.5 wt.%时,常压下试样的显气孔率最低为25.3%、体积密度最高为1.97 g·cm^(-3),常温抗弯强度最高为33.8 MPa;气压下试样的显气孔率最低为20.8%,体积密度最高为2.15 g·cm^(-3),常温抗弯强度最高为43.4 MPa。与常压相比,2 MPa气氛压力烧成的试样,纤维状的Si_(3)N_(4)晶须明显偏少,柱状的Si_(3)N_(4)晶须明显偏多。
BN/SiC/Si_(3)N_(4)composite ceramics were prepared through in-situ nitridation reaction sintering with BN,Si,SiC powders,Ti-Si-Fe alloys and phenolic resin(PFF)as raw materials and B_(2)O_(3)as sintering aid.Mechanical properties of the samples,depending on the content of Ti-Si-Fe alloys to partially replace silicon powder and nitrogen pressure,were evaluated and discussed.The presence of Fe,Mn and other elements in the Ti-Si-Fe alloy promoted the nitridation of silicon and the growth of silicon nitride whiskers.All the nitridized products were filled into the pores and hence improved densification of the sample,so that mechanical properties of the materials were enhanced.When the content of Ti-Si-Fe alloy is 1.5 wt.%,the sample has the lowest apparent porosity(25.3%)and the highest bulk density(1.97 g·cm^(-3)),meanwhile the highest bending strength is 33.8 MPa at ambient pressure.At gas pressure of 43.4 MPa,the corresponding lowest apparent porosity is 20.8%and the highest bulk density is 2.15 g·cm^(-3).After sintering at gas pressure of 2 MPa,the growth of fiber-like Si_(3)N_(4)crystals might be significantly suppressed,while that of columnar Si_(3)N_(4)crystals was significantly boosted.
作者
李立倍
张锦化
冯邻江
张祖力
龙图
陈祥惠
周寻
徐晟
李灵转
LI Libei;ZHANG Jinhua;FENG Linjiang;ZHANG Zuli;LONG Tu;CHEN Xianghui;ZHOU Xun;XU Sheng;LI Lingzhuan(Chongqing Materials Research Institute Co.,Ltd.,Chongqing 400707,China;National Engineering Research Center for Instrument Functional Materials,Chongqing 400707,China;The State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,Hubei,China;Zhejiang Green City Construction Technology Co.,Ltd.,Hangzhou 310013,Zhejiang,China)
出处
《陶瓷学报》
CAS
北大核心
2024年第3期575-583,共9页
Journal of Ceramics
基金
国家重点专项(2023YFB3210002)。
