Ti对Fe-Cr-Ni-Al合金抗氧化性能的影响  

Effect of Ti on oxidation behavior of Fe-Cr-Ni-Al alloy

作　　者：吴彩霞[1,2] 尹付成[1,2] 李智[1,2] 赵满秀[1,2] 龙朝辉[1,2] 

机构地区：[1]湘潭大学机械工程学院,湘潭411105 [2]湘潭大学材料设计及制备技术湖南省重点实验室,湘潭411105

出　　处：《粉末冶金材料科学与工程》2013年第4期491-496,共6页Materials Science and Engineering of Powder Metallurgy

基　　金：国家自然科学基金资助项目(51071135);教育部博士点专项科研基金资助项目(20114301110005);湖南省高等学校科学研究项目(12A128)

摘　　要：采用增质(质量增加)法研究Ti对显微组织为γ-Ni+γ′-Ni3Al的Fe-Cr-Ni-Al镍基合金和显微组织为α-Fe+β-NiAl的Fe-Cr-Ni-Al铁基合金在900℃下的高温氧化行为的影响。利用扫描电镜、能谱仪以及X射线衍射对氧化物的形貌、成分和相组成进行分析。结果表明:Fe-Cr-Ni-Al合金在900℃下氧化的质量增加遵循抛物线规律;当Fe-Cr-Ni-Al镍基合金中加入Ti后,合金表面形成一定的保护性较差的TiO2,随Ti含量增加,TiO2增多,发生严重的内氧化,导致合金抗氧化性能变差;而Fe-Cr-Ni-Al铁基合金中加入适量Ti时,合金表面形成保护性良好的Al2O3氧化膜,且Ti在晶界偏析,生成的TiO2将连续的外氧化膜和基体钉扎在一起,增加氧化膜的附着力,从而改善合金的抗氧化性能。但随Ti含量提高,Ti的偏聚程度增加,晶界上形成较多的TiO2,导致一定程度的内氧化,使铁基合金的抗氧化性能降低。The effect of Ti on the oxidation behavior of nickel-based and iron-based Fe-Cr-Ni-Al alloys with microstructures of γ-Ni＋γ′-Ni3 Al and α-Fe＋β-NiAl,respectively,were investigated by means of mass gain method at 900 ℃.SEM-EDS and XRD were used to reveal the morphologies and phase composition of the oxidation products and determine their phase structures,respectively.The results indicate that oxidation kinetics of Fe-Cr-Ni-Al alloys obey parabolic law.Regard to nickle-based alloys,a certain content TiO2 film with poor protective effect will be formed on the surface of alloys by the addition of Ti.With increasing Ti content,serious internal oxidation takes place in the nickle-based alloys due to the amount of TiO2 increase,which results in the oxidation resistance decrease.On the contrary,with the addition of Ti to iron-based alloys,Al2 O3 protection oxidation film forms and Ti segregates on the grain boundary.The formed TiO2 can pin together with the continuous outer oxide film and substrate which is beneficial to the adhesion of oxidation film,so the oxidation resistance improves.However,with the increasing of Ti content,Ti segregation on the grain boundary becomes more intense.More TiO2 will be formed on the grain boundary which leads to certain internal oxidation,making the oxidation resistance decrease.

关 键 词：TI Fe-Cr-Ni-Al合金 抗氧化性 偏析 

分 类 号：TG172.3[金属学及工艺—金属表面处理]