TiAl合金表面Al-Y渗层的组织及高温抗氧化性能  

Microstructure and High Temperature Oxidation Properties of Al-Y Co-deposition Coating on TiAl Alloy

作　　者：李涌泉 郝清锐[2] 梁国栋 王存喜 高阳 LI Yongquan;HAO Qingrui;LIANG Guodong;WANG Cunxi;GAO Yang(College of Mechatronic Engineering,North Minzu University,Yinchuan 750021;School of Material Science&Engineering,North Minzu University,Yinchuan 750021)

机构地区：[1]北方民族大学机电工程学院,银川750021 [2]北方民族大学材料科学与工程学院,银川750021

出　　处：《机械工程学报》2025年第4期137-146,共10页Journal of Mechanical Engineering

基　　金：国家自然科学基金(52161009,51961003);西部之光(XAB2022YW07);过程装备与控制工程四川省高校重点实验室(GK202309);宁夏复合制造系统工程技术研究中心(2023GCJS008)资助项目。

摘　　要：通过930℃下保温2h的扩散渗工艺在TiAl合金表面制备Al-Y渗层,采用SEM、XRD、EDS分析渗层的组织结构及相组成,对比研究TiAl基体及渗层在1000℃下的高温氧化性能。结果表明:该工艺下制备的渗层厚约为53μm,具有复合结构,由外向内依次为Ti Al_(3)、TiAl_(2)浅表层,TiAl_(3)中间层和TiAl_(2)内层,且渗层与基体为良好的冶金结合。高温氧化试验表明:TiAl基体氧化过程中形成的富Ti氧化物外层和TiO_(2)+Al_(2)O_(3)次外层,氧化膜结构疏松,无法阻碍O元素的内扩散,导致氧化膜反复剥落,最终引发灾难性氧化;Al-Y渗层在氧化时表面形成致密的Al_(2)O_(3)膜层,阻碍了O元素的内扩散,有效地提高了合金的高温抗氧化性能,随着氧化时间的延长,氧化后期Al元素的内/外扩散及Ti的外扩散导致渗层表面氧化膜发生剥落,但未剥落的残余渗层依旧与基体保持着良好的冶金结合,对基体合金的抗高温氧化仍具备保护性。The Al-Y co-deposition coatings on TiAl alloy are prepared by pack cementation processes at 930℃for 2 h,scanning electron microscope,X-ray diffraction and energy dispersive spectrometry are employed to investigate the microstructure phase composition of the coatings.High temperature oxidation properties of both alloy and coating are comparatively investigated.The results show that the coating prepared by this process have a good metallurgical combination with the alloy and a composite structure with a thickness of 53µm,mainly composed of a TiAl_(3),TiAl_(2)outer layer,a TiAl_(3)middle layer and a TiAl_(2)inner layer.High temperature oxidation experiments showes that:the loose Ti-rich oxide outer layer and TiO_(2)+Al_(2)O_(3)secondary outer layer formed on the surface of TiAl matrix during the oxidation process could not hinder the internal diffusion of O element,resulting in the repeated peeling of oxide film,and eventually leading to catastrophic oxidation.Moreover,dense Al_(2)O_(3)film is formed on the Al-Y coating during oxidation,which hinders the internal diffusion of O element and effectively improves the high-temperature oxidation resistance of the alloy.With the prolonged of oxidation time,the inner/outer diffusion of Al and the outer diffusion of Ti leading to the peeling off of the oxide film,but the remaining layer still maintained good metallurgical bonding with the alloy and still have certain protective properties.

关 键 词：TIAL合金 Al-Y渗层 组织结构 高温氧化 

分 类 号：TG174[金属学及工艺—金属表面处理]