TiAl合金表面阴极微弧沉积Al2O3陶瓷涂层的生长过程与相组成  

Microstructure Evolution of Al2O3 Ceramic Coatings Fabricated on TiAl Alloy via Cathodic Plasma Electrolytic Deposition

作　　者：王少青 谢发勤[1] 吴向清[1] 陈连阳 周恺 Wang Shaoqing;Xie Faqin;Wu Xiangqing;Chen Lianyang;Zhou Kai(Northwest Polytechnical University,Xi’an 710072,China;Northwest Institute for Nonferrous Metal Research,Xi’an 710016,China)

机构地区：[1]西北工业大学,陕西西安710072 [2]西北有色金属研究院,陕西西安710016

出　　处：《稀有金属材料与工程》2019年第12期3883-3888,共6页Rare Metal Materials and Engineering

基　　金：陕西省科技计划发展项目（2018JZ5004）

摘　　要：利用阴极微弧沉积技术在预处理后的TiAl合金表面制备了Al2O3陶瓷涂层,研究了涂层的生长过程和相组成。采用扫描电子电镜(SEM、EDS)、透射电子电镜(TEM)、X射线衍射(XRD)等方法,对Al2O3涂层的生长过程中的微观形貌、组织成分以及晶体结构的演变进行了研究与分析。结果表明,TiAl合金表面阴极微弧沉积过程中,在阴极表面发生非晶态Al(OH)3的吸附、脱水烧结形成Al2O3陶瓷涂层的沉积。Al2O3涂层生长分前期I、中期II和后期III 3个阶段,前期起弧阻挡层被击穿,涂层生长较慢、组织致密且与基体结合良好;反应中期涂层生长较快,Al(OH)3不断吸附和脱水烧结,涂层结晶度提高;反应后期涂层生长速度变缓,表层组织疏松、多孔,相组成为87.5%的α-Al2O3和12.5%的γ-Al2O3。In order to study the microstructure evolution of Al2O3 ceramic coatings during cathodic plasma electrolytic deposition(CPED) process, Al2O3 coatings were fabricated via CPED technique on prepared TiAl alloy in Al(NO3)3 electrolyte with different time. Microstructure, morphology and chemical compositions of coatings were analyzed by scanning electron microscopy(SEM) with energy-dispersive spectroscopy(EDS), transmission electron microscopy(TEM) and X-ray diffraction(XRD), and heat-resistance of TiAl alloy substrate and CPED coating was tested. The results indicate that the growth process is divided into three stages, i.e. the initial stage, the medium stage and the late stage. The barrier layer is broken down and the coating grows slower in the initial stage, and has uniform and good combination with the substrate. The CPED coating grows stably and more rapidly in the medium stage, and the crystallinity of the CPED coating improves. In the late stage, the CPED coating grows slower, containing 87.5% main phase α-Al2O3 and 12.5% γ-Al2O3, and the loose and porous outer coating is fabricated.

关 键 词：阴极微弧沉积 TIAL合金 微观组织结构演化 结晶度 

分 类 号：TG174.453[金属学及工艺—金属表面处理] TG146.23[金属学及工艺—金属学]