【摘要】 在GH5 36高温合金基材上等离子喷涂NiCrA1Y/8wt.%Y2 O3 -ZrO2 热障涂层后 ,采用积分化矩形光斑进行激光重熔。组织结构分析及热震试验结果表明 :等离子喷涂与激光重熔试样的失效形式和机理不同 ,等离子喷涂试样以热震应力失效和热震应力复合TGO应力辅助作用两种形式失效。激光重熔试样以热震应力形式失效为主。能量密度较小的激光重熔试样具有高于等离子喷涂试样的热震寿命。网状裂纹及柱状晶粗化和扩展到喷涂态陶瓷层中的裂纹是激光重熔试样热震寿命降低的主要原因。更多还原

【Abstract】 A CO 2 continuous wave laser with BIZ transmissive beam integrators was used for laser remelting(LR) the surface of plasma sprayed(PS) ZrO 2-8wt pct Y 2O 3(8YSZ)/Ni22Cr10A1Y thermal barrier coatings (TBCs) on GH536 superalloy substrate.The uniform energy distribution of beam with rectangular profiles of 9mm×3mm was obtained.The thermal shock tests were conducted to both PS samples and LR samples at 1050℃.With the different failure criterions,the mechanism of failure was discussed.It was indicated that the higher laser energy input is harmful for thermal shock lifetime of LR TBCs.The thinner remelted thickness of 50μm～80μm were suggested for longest thermal shock lifetimes.更多还原