HCPEB作用下镀铝CoCrAlY涂层的高温氧化行为

High temperature oxidation and thermal shock properties of thermal barrier coating by CoCrAlY surface modification

使用大气等离子喷涂在镍基高温合金表面制备Co Cr Al Y粘结层并蒸镀一定厚度的纳米铝膜,利用强流脉冲电子束辐照镀铝涂层表面.采用高温氧化试验,观察并分析涂层的高温氧化行为.XRD结果表明,强流脉冲电子束辐照镀铝涂层表层快速氧化生成大量Al_2O_3;100 h氧化后,表层氧化物成分较为稳定,基本保持Al_2O_3较多.尖晶石类氧化物较少的状态.表面形貌分析结果表明,经过强流脉冲电子束辐照镀铝涂层在高温环境下能够保持表层的致密和完整,缺陷很少.涂层表层含有大量均匀且较为致密的Al_2O_3能够有效抵御外界环境的进一步氧化,有较好的的抗高温氧化性能.

CoCrAlY coating was prepared by air plasma spray(APS)on the surface of Ni-based superalloy,nano-scale Al film was deposited on the surface of CoCrAlY by electron beam evaporation and modified by high current pulsed electron beam and the deposition of ceramic coating on CoCrAlY surface by APS.The high temperature oxidation test and thermal shock test of the thermal barrier coating in air atmosphere were carried out.The results show that the thermally grown oxide(TGO)generated at the interface in the thermal barrier coating of modified CoCrAlY has high continuity and compactness after high temperature oxidation at 1 050℃in static air,which can effectively hinder the further development of oxidation and avoid the formation of corner oxide,and then the resistance properties of the thermal barrier coating are improved.The thermal shock tests were conducted by heat to 1 050℃and water quenching at 10℃,the rate of abscission of thermal barrier coating is only about 2%.