Ti_2AlNb基合金表面磁控溅射Al/Al_2O_3薄膜及扩散处理对其抗高温氧化性能的影响  

Effect of Diffusion Treatment on High Temperature Oxidation Resistance of Magnetron Sputtered Al/Al_2O_3 Film on Ti_2AlNb Alloy Substrate

作　　者：崔世宇 缪强[1] 梁文萍[1] 徐一[1] 杨晶晶[1] 张志刚[1] 

机构地区：[1]南京航空航天大学材料科学与技术学院,江苏南京211106

出　　处：《材料保护》2015年第2期47-50,8,共4页Materials Protection

基　　金：国家自然科学基金面上项目(51174119);航空科学基金(2012ZF52071);南京航空航天大学博士学位论文创新与创优基金(BCXJ-1411)资助

摘　　要：为提高Ti2Al Nb合金的抗高温氧化性能,在Ti2AlNb合金表面磁控溅射Al/Al2O3薄膜,于真空退火炉内对其进行600℃,1 h扩散处理后,分别在650,750,850℃下氧化100 h。利用XRD,SEM,EDS技术对基体和扩散试样的相组成、微观形貌进行了分析;研究了Al/Al2O3薄膜扩散层的抗高温氧化性能及扩散处理对Al/Al2O3薄膜氧化动力学曲线的影响。结果表明:Al/Al2O3薄膜扩散层的氧化行为受氧离子渗入薄膜运动过程的控制,在高温条件下表层形成连续致密的Al2O3膜,使薄膜扩散层的氧化系数远低于基体,并且次表层的富铝相能有效阻止氧离子扩散通道的形成,减少基体与氧化性气体接触,从而显著提高Ti2Al Nb基合金的抗高温氧化性能。Al/Al_2O_3 film prepared on Ti_2 AlNb alloy substrate by magnetron sputtering was diffusion treated at 600 ℃ for 1 h so as to improve the oxidation resistance of the alloy at elevated temperature.As-prepared Al/Al_2O_3 film after diffusion treatment was oxidized at 650.750,850℃ for 100 h,and its high-temperature oxidation resistance was evaluated.Moreover,the phase structure,morphology and elemental composition of the alloy substrate and the diffusion-treated Al/Al_2O_3 film were analyzed by X-ray diffraction,scanning electron microscopy and energy dispersive spectrometry,and the effect of diffusion treatment on the oxidation kinetics of the Al/Al_2O_3 film was investigated.Results showed that the oxidation behavior of the diffusion layer of Al/Al_2O_3 film was controlled by the permeation of O^(2-) ion.At elevated temperatures,a continuous and compact Al_2O_3 layer was formed on the surface of Al/Al_2O_3 film thereby significantly reducing the oxidation coefficient of the diffusion layer.Besides,the subsurface Al-rich phase could effectively prevent the formation of diffusion channels for O^(2-) ion and inhibit the contact between the substrate and oxidizing gas,thereby significantly improving the oxidation resistance of the Ti_2AlNb alloy at elevated temperature.

关 键 词：磁控溅射 Al/Al2O3薄膜 扩散处理 抗高温氧化性能 氧化系数 

分 类 号：TG174.4[金属学及工艺—金属表面处理]