摘要
采用电弧离子镀(AIP)技术在CoCrNiAlY-YSZ-LaMA双陶瓷涂层表面沉积一层Al镀层,利用XRD、SEM和EDS等微尺度分析表征方法,全面解析涂层在大气暴露过程中的高温氧化行为。研究结果表明,未镀铝LaMA层在氧化过程中发生严重体积收缩,导致纵向微裂纹萌生和扩展。这些微裂纹成为氧气向内部扩散的通道,导致涂层呈现持续氧化增重趋势、TGO快速生长和严重的元素扩散,并最终加剧涂层断裂失效。但镀铝涂层样品表现出更好的高温抗氧化性能与结构稳定性,高温氧化过程中,表面Al镀层与氧气发生原位反应生成致密Al2O3屏障层,有效阻止或延迟氧气内部渗透,使TGO缓慢生长,其氧化增重从20h时的8.59mg/cm^(2)略微上升到80h时的9.46mg/cm^(2)。本研究结果为双陶瓷热障涂层的延寿设计与界面热生长应力调控开辟出全新技术途径和理论视野。
An Al plating layer was deposited on the surface of CoCrNiAlY-YSZ-LaMA dual ceramic coating by arc ion plating(AIP).The high temperature oxidation behaviors of these coatings during the air exposure were comprehensively characterized by using XRD,SEM and EDS.Results showed that LaMA coating without Al plating layer underwent severe volume shrinkage during the oxidation test,which triggered the initiation and propagation of longitudinal micro-cracks.These micro-cracks acted as the internal diffusion channels for O2,triggering a sustained mass increase tendency,rapid TGO growth and severe elemental diffusion,and consequently resulted in a serious coating fracture.However,the coating with Al plating layer showed better high-temperature oxidation resistance and structural stability.The surface Al layer reacted with O2 to generate an in situ dense Al2O3 barrier layer during the oxidation process,which prevented or delayed the internal penetration of O2,and thus resulted in a very slow growth rate of TGO layer.The weight gain of this sample increased slightly from 8.59 mg/cm^(2) at 20 h to 9.46 mg/cm^(2) at 80 h.These current experimental results provided a new technical way and theoretical vision for the life-extension design of dual-ceramic thermal barrier coatings and the regulation of interfacial thermal growth stress.
作者
解志文
陶浩天
刘天新
陈永君
胡素影
马北一
XIE Zhiwen;TAO Haotian;LIU Tianxin;CHEN Yongjun;HU Suying;MA Beiyi(University of Science and Technology Liaoning,Anshan 114051,China)
出处
《航空制造技术》
CSCD
北大核心
2024年第4期58-63,共6页
Aeronautical Manufacturing Technology
基金
辽宁省教育厅基础科研项目(JYTMS20230941)。
关键词
双陶瓷热障涂层
Al镀层
高温抗氧化性能
热生长氧化物(TGO)
结构稳定性
Double ceramic thermal barrier coating
Al plating
High-temperature oxidation resistance
Thermally grown oxide(TGO)
Structural stability
