TC4合金双辉等离子渗Cr高温氧化行为  

Effect of double glow plasma surface chromizing on high-temperature oxidation resistance of TC4 titanium alloy

作　　者：魏东博[1] 张平则[1] 姚正军[1] 梁文萍[1] 缪强[1] 徐重[1] 

机构地区：[1]南京航空航天大学材料科学与技术学院,江苏南京211100

出　　处：《材料热处理学报》2011年第10期146-150,共5页Transactions of Materials and Heat Treatment

基　　金：航空科学基金资助项目(2007ZE52057);江苏省普通高校研究生科研创新计划资助项目(CXZZ11_0203)

摘　　要：研究了双层辉光等离子渗Cr对TC4合金650、750、850℃恒温氧化性能的影响。结果表明:渗Cr后,表面梯度合金层显著提高了TC4合金的高温氧化性能,Ti-Cr互扩散层可有效阻止氧向基体扩散。氧化过程中,Ti、Cr向外扩散形成TiO2/Cr2O3氧化膜,其形态与氧化温度有关。850℃氧化100 h后,渗Cr试样表面形成致密Cr2O3膜,恒温氧化性能优于NiCrAlY热障涂层。Isothermal oxidation behavior of TC4 titanium alloy,which was chromized by the double glow plasma surface alloying technology（DGP）,were investigated at 650 ℃,750 ℃ and 850 ℃.The results show that the chromizing layer consists of surface loose layer,compact deposited layer and Ti-Cr mutual diffusion layer.The diffusion layer has better oxidation resistance compared with NiCrAlY thermal barrier coating.The ratio of Cr to Ti content in the diffusion layer exhibits gradient distribution by Cr,Cr1.97Ti1.07 and CrTi4.Under oxidation circumstance,Cr,Ti and Al diffuse outward to form multilayer oxide films,which prevent inward diffusion of oxygen.At 650 ℃,the oxidation films consist of two layers： the external Cr2O3 layer and the internal TiO2 layer.At 750 ℃,a mixed oxide layer containing Cr2O3 and TiO2 is formed beneath the Cr2O3 layer and TiO2 layer,whereby Ti（Cr,Al）2 Laves phase is observed in the Ti-depleted layer.At 850 ℃,a mixed oxide layer containing TiO2,Ti2O3 and Ti3O5 is formed beneath the Cr2O3 layer and Al2O3 layer,whereby Ti（Cr,Al）2 Laves phase and Kirkendall voids are formed in the depletion layer.

关 键 词：钛合金 双辉等离子表面合金化 高温氧化 

分 类 号：TG174.44[金属学及工艺—金属表面处理]