Ti-44Al-8Nb-1B合金在700℃下的氧化行为  

Oxidation Behaviors of Ti-44Al-8Nb-1B Alloy at 700 ℃

作　　者：李作良[1] 黄泽文[2] 

机构地区：[1]西南交通大学材料科学与工程学院,四川成都610031 [2]西南交通大学材料先进技术教育部重点实验室,四川成都610031

出　　处：《钛工业进展》2010年第5期10-15,共6页Titanium Industry Progress

基　　金：国家自然科学基金资助项目(50971106)

摘　　要：对全片层结构的γ-TiAl基合金Ti-44Al-8Nb-1B在700℃大气环境中的表面氧化行为进行了系统的研究。研究发现,这种高铌合金表面形成的氧化层由TiO2和Al2O3混合构成。这种高Nb合金的表面氧化导致了室温塑性的明显降低,但强度指标变化不大。相对于单纯手动抛光,手动+电解抛光能够适度提高合金表面的氧化抗力,但这种提高并未带来拉伸性能的增加。研究还发现,1 000 h氧化后,样品表面的硼化物和晶界表现出较片层晶团严重的氧化行为,分析认为这分别是硼化物缺铝和在晶界各种元素扩散较快的缘故。A fully lamellar γ-TiAl based alloy Ti-44Al-8Nb-1B was investigated on its oxidation behavior in this study.It was found that the oxide scales formed on the alloy surface are composed of TiO2 and Al2O3 when exposed to the 700 ℃ air.As a result,the room temperature ductility of the alloy is deteriorated significantly,while the strength remains essentially unchanged.Compared with only manual polishing samples,the manual polishing plus electropolishing samples can improve the oxidation resistance slightly but result in no improvement in tensile properties.It was also found that the borides on the surface and grain boundaries tend to oxidize faster than α2 lamellae matrix probably because of the depletion of Al in the borides and faster diffusion along the grain boundaries.

关 键 词：Γ-TIAL基合金 抗氧化性 高铌 硼化物 

分 类 号：TG172[金属学及工艺—金属表面处理]