摘要
以Si粉、h-BN、Si3N4为原料,配制成h-BN添加量分别为20%、25%、30%(w)的混合料,经振动磨混合、等静压成型、氮化烧结(1 400℃保温5 h),制成Si3N4-BN复合材料试样。分析试样的物相组成,并检测其显气孔率、体积密度、常温强度、高温强度、弹性模量、热膨胀系数等性能指标;利用有限元分析软件ANSYS分析w(h-BN)=30%的试样在模拟薄带连铸条件下的抗热震性,然后采用熔融金属热冲击方法对不同温度(分别为650、750和850℃)保温30 min烘烤后w(h-BN)=30%的试样进行抗热震试验。结果表明:1)随着h-BN添加量的增加,Si3N4-BN复合材料的烧结性能下降,强度、弹性模量、热膨胀系数减小。2)w(h-BN)=30%的Si3N4-BN复合材料的抗热震性能可以满足现有薄带连铸生产的工况条件,有望成为热压h-BN的代替品。
Si3 N4-BN composite specimens were prepared using Si powder,h-BN （20%,25% and 30%,in mass,the same hereinafter）and Si3 N4 as raw materials,mixing in a vibromill,isostatic pressing,firing in nitrogen at 1 400 ℃ for 5 h.The phase compositions were examined,the apparent porosity,bulk density,cold and high temperature strengths,modulus of elasticity and thermal expansion coefficient were determined. The thermal shock resistance of specimens with 30% h-BN in simulated thin strip continuous casting conditions was analyzed adopting finite element software ANSYS,and the thermal shock tests were carried out using molten metal thermal shock method on specimens （30% h-BN）insulated at different temperatures （650,750 and 850 ℃）for 30 min.The results show that：（1）with h-BN addition increasing,the sintering performance declines,the strength,modulus of elasticity,and thermal expansion coefficient decrease;（2）the thermal shock resistance of the Si3 N4-BN composite with 30% h-BN can meet the requirement of thin strip continuous casting currently,the composite promises to be the substitute of hot pressing h-BN.
出处
《耐火材料》
CAS
北大核心
2015年第1期36-38,42,共4页
Refractories
基金
国家自然科学基金资助项目(51372231)
关键词
氮化硅
六方氮化硼
薄带连铸
侧封板
氮化烧结
反应烧结
抗热震性
silicon nitride
hexagonal boron nitride
thin strip continuous casting
side seal plate
reaction sintering
thermal shock resistance
