EB-PVD热障涂层对高温合金基体断裂特征影响的研究

采用EB－PVD方法在K3合金上（包括铸态和经标准热处理两种状态）沉积了由NiCoCrAlY金属粘结层和YSZ涂层顶层组成的双层结构的热障涂层，对未涂层和涂层试样的拉伸性能进行了评估，并分析了涂层的制备和中间处理过程中的基体的微观结构的变化。结果表明，在热障涂层的沉积以及中间处理过程中（真空前处理及后处理），基体的铸态组织得到改善，产生了析出强化，使得在铸态K3合金基体上沉积热障兴层后基体的拉伸强度由800MPa提高到1050MPa，而在经过标准热处理的合金基体上沉积热障涂层对基体的力学性能几乎没有影响。

Effect of EB-PVD thermal barrier coatings on fracture characteristics of superalloy substrate

Two layered thermal barrier coatings(TBCs) consisting of NiCoCrAlY bond coating and YSZ (Yttria Stablized Zirconia) top coating have been produced by means of electron beam physical vapor deposition (EB-PVD) onto substrate of K3 superalloy (involving as cast and standard heat treated states). Tensile behavior was evaluated for the specimens with and without TBC. Microstructure changes were analyzed in the preparation and inter mediate heat treatments of coating. It was found that, due to the deposition of TBC onto the as cast K3 substrate and inter mediate heat treatment (vacuum pre heating and heating treatments), the cast microstructure of the substrate was improved. Heat treatment can result in a precipitation hardening. The tensile strength of K3 substrate was improved from 800 MPa to 1 050 MPa after TBCs deposition, whereas the deposition of TBC has almost no effect on the mechanical behavior of the specimen that dealed with pre heat treatment.