陶瓷涂层/GH202合金界面显微组织的演化

来源期刊：中南大学学报(自然科学版)2001年第4期

论文作者：古一 夏长清 曾凡浩

文章页码：402 - 404

关键词：高温无机涂层;高温合金;扩散反应层

Key words：high-temperature inorganic coating; high-temperature alloy; diffusion interaction layer

摘    要：航天发动机工作时,要求燃气通道内表面具有优越的抗高温、抗氧化性能和良好的机械性能.作者在GH202合金制备的火箭发动机关键零件表面加涂高温无机涂层,并通过光学显微镜、扫描电镜、能谱分析及硬度测试,观察和分析了涂层/GH202合金界面显微组织的演化.研究结果表明:GH202合金表面高温无机涂层经历了1 000℃ 25℃的50次热循环后,涂层无崩裂、脱落现象,涂层与基体结合牢固,性能良好.在1 000℃时的扩散退火过程中,合金中的Cr元素向涂层/基体合金界面扩散,在涂层一侧形成富Cr元素的化合物层,在基体一侧形成富 Ti,Al元素的晶间氧化物层;涂层中主要元素Si向金属基体中扩散.为提高涂层与基体合金的结合强度以及涂层的热腐蚀性能提供了依据.

Abstract: The super oxidization and high temperature resistance, and good mechanical behavior of the surface of the gasjet channel are required when the airspace works. In order to protect the surface, the high-temperature inorganic coating has been applied and the microstructures of the interface between the super alloyGH202 and the coating have been investigated. The results show that the coating has strong oxidization resistance. It hasn’t separated from the substrate and no crack can be detected even after 50 times of heat-cycle experiments from1 000℃to 25℃, furthermore it is combined to the substrate very well. A compound layer is formed in the coating in which the concentration of Cr is relatively high because of the diffusion from the substrate to the coating and a pauperization layer is formed. While diffusion annealing at 1 000℃, the main element Si in the coating diffuses into the substrate, as a result of an oxidization layer on the boundaries appears along the interface of alloy. The ways of increasing the bond strength between the coating and the substrate and the heat erosion performance of the coating can be achieved based on the study.