摘要
以Si C、炭黑和热固性酚醛树脂为主要原料,配制成Al粉外加量分别为0和4%(w)的两种试样,经混料、成型、180℃固化、800℃炭化后,在石墨坩埚中用单质Si掩埋,在真空条件下分别经1 550、1 600、1 650和1 700℃烧成反应烧结碳化硅。结果表明:1)未添加和添加4%(w) Al粉的试样经1 550~1 700℃烧成后,其主要物相均为α-SiC、β-Si C和游离Si。2)添加4%(w) Al粉试样的烧后线变化更小;经1 600℃烧成后残余Si量最低,SiC含量最高,综合性能最优。3) Al具有较大的可塑性,添加4%(w) Al粉试样的成型致密度更高,气孔更少更小,在反应烧结过程中液态Si渗入的阻力更大,渗入量更少,最终残余量也更少,试样的高温强度更高;经1 700℃烧成生成Al4SiC4,增强了物料颗粒之间的结合。
Reaction-sintered silicon carbide specimens were prepared using SiC,carbon black,and thermosetting phenolic resin as raw materials,extra adding metal Al powder(0,and 4 mass%),mixing,shaping,curing at 180℃,and carbonizing at 800℃,and firing in vacuum at 1550℃,1600℃,1650℃and 1700℃,respectively,in graphite crucibles embedded by Si powder.The results show that:(1)the main phases of the specimens with 4%or without Al powder areα-SiC,β-SiC and free Si;(2)the specimen with 4%Al powder has lower permanent linear change;after firing at 1600℃,the specimen has the lowest residual Si content and the highest SiC content,and performs the best properties;(3)Al has great plasticity;the specimen with 4%Al powder has high density and low porosity;during the reaction sintering process,the resistance of liquid Si infiltration is greater,the amount of infiltration is less,so the final residual amount is less,so the hot strength of the specimen is higher;after firing at 1700℃,Al 4SiC 4 forms,increasing the bonding among the particles.
作者
艾俊迪
余超
董博
丁军
祝洪喜
邓承继
张春晓
Ai Jundi;Yu Chao;Dong Bo;Ding Jun;Zhu Hongxi;Deng Chengji;Zhang Chunxiao(The State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,Hubei,China)
出处
《耐火材料》
CAS
北大核心
2021年第1期51-55,共5页
Refractories
基金
湖北省自然科学基金创新群体项目(No.2018CFA022)
湖北省自然科学基金和武汉科技大学国防预研基金项目(GF201913)联合资助。
关键词
反应烧结
碳化硅
铝粉
残余硅
显微结构
reaction sintered
silicon carbide
aluminum powder
residual silicon
microstructure
