摘要
采用Si-CeO2包埋共渗的工艺在铌硅基超高温合金表面制备了Si-Ce共渗层,研究了其在1250℃时的恒温氧化性能。采用XRD、SEM及EDS分析了Si-Ce共渗层氧化前后的相组成、组织形貌及微区成分。结果表明:Si-Ce共渗层具有明显分层的结构,由外至内依次为(Nb,X)Si2(X表示Ti,Hf和Cr)外层和(Ti,Nb)5Si4过渡层,且Si-Ce共渗层的生长符合抛物线的动力学规律;1250℃的氧化结果显示,Si-Ce共渗层的氧化动力学曲线遵循抛物线规律,其抛物线速率常数比未制备渗层的基体合金低4个数量级,说明其具有优异的高温抗氧化性能。
Si-Ce co-deposition coating was prepared on Nb-Si based ultrahigh temperature alloy by pack cementation process. The microstructure and high temperature oxidation resistance of the coating were studied. The results show that all the coating is composed of （Nb, X）Si2 （X represented Ti, Hfand Cr） outer layer and （Ti, Nb）5Si4 transitional layer. The coating growth kinetics respectively at 1050 ℃, 1150 ℃ and 1250 ℃ are all fitted well to parabolic laws. The Si-Ce co-deposition coating possesses much better oxidation resistance than the bare Nb-Si based ultrahigh temperature alloys.
出处
《热加工工艺》
CSCD
北大核心
2012年第20期134-137,共4页
Hot Working Technology
基金
国家自然科学基金资助项目(50871087)
国家"111"引智基金项目课题(B080401)
关键词
铌硅基超高温合金
Si-Ce共渗层
包埋渗
共渗层结构
高温抗氧化性能
Nb-Si based ultrahigh temperature alloy
Si-Ce co-deposition coating
pack cementation
co-depositioncoating structure
high temperature oxidation resistance
