热暴露对带热障涂层DD6单晶高温合金组织的影响

采用0.3 MPa压力对DD6单晶高温合金进行水吹砂，然后用电子束物理气相沉积的方法在DD6合金基体上制备了热障涂层，将带热障涂层试样置于1100℃空气气氛中分别进行50 h和100 h热暴露，在1100℃/130 MPa条件下测试持久性能。研究了水吹砂及高温热暴露对带热障涂层DD6合金组织的影响。结果表明：0.3 MPa压力水吹砂制备热障涂层并高温热暴露后没有发现再结晶组织；热暴露过程中，基体和涂层之间的元素会发生不同程度的互扩散；表面残余应力和元素互扩散导致了γ′相粗化方向的变化；性能测试后试样断口附近的涂层与基体界面下方局部区域形成了二次反应区。

Effects of Thermal Exposure on Structures of DD6 Single Crystal Superalloy with Thermal Barrier Coatings

In order to investigate the effect of water grit-blasting and high temperature thermal exposure on the microstructures of DD6 alloy with TBCs, DD6 single crystal superalloy specimens were water grit-blasted with 0. 3 MPa pressure, then the specimens were coa-ted with thermal barrier coatings by electron beam physical vapor deposition ( EB-PVD) . Specimens with TBCs were exposed at 1100℃ for 50 and 100 hours in the air respectively, and then these specimens were subjected to stress-rupture tests under the condition of 1100 ℃/130 MPa. The results show that grit-blasting doesn’ t lead into the recrystallization, thermal exposure can induce element in-terdiffusion between the bond coat and alloy substrate, the residual stress and element diffusion lead into the changes ofγ′phase coar-sing direction. After stress rupture tests, the secondary reaction zone emerges into a local area.