铌硅基超高温合金Si-Ce共渗层的组织及高温抗氧化性能  

Microstructure and High Temperature Oxidation Resistance of Si-Ce Co-deposition Coating on Nb-Si Based Ultrahigh Temperature Alloy

作　　者：张艺[1] 郭喜平[1] 

机构地区：[1]西北工业大学凝固技术国家重点实验室,陕西西安710072

出　　处：《热加工工艺》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)

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.

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 

分 类 号：TG174[金属学及工艺—金属表面处理]