等离子喷涂热障涂层残余应力的实验与模拟研究(英文)

Experimental and Numerical Investigation of Residual Stresses in Plasma-sprayed Thermal Barrier Coatings

分别采用真空和大气等离子体喷涂工艺在GH3128镍基高温合金基材表面制备CoNiCrAlY结合层和氧化钇部分稳定的氧化锆陶瓷层组成热障涂层。采用有限元模拟计算了涂层的残余应力,研究了基材预热对打底层与陶瓷层界面应力分布的影响规律。结果表明,预热基材可以显著地降低陶瓷顶层内部产生的残余拉应力。采用钻孔法测量了涂层中的残余应力并与模拟结果作定量比较,结果表明:有限元模拟计算结果与实验测量结果能较好吻合。

Finite element analysis （FEA） was performed to analyze residual stresses development within thermal bar- tier coatings system consisting vacuum plasma sprayed CoNiCrA1Y bondcoat and atmospheric plasma sprayed yttria partially stabilized zirconia topcoat on the GH3128 nickel-based superalloy substrates. The effect of substrate preheat- ing process on the residual stress generated at the bondcoat/topcoat interface was evaluated. The results show that sub- strate preheating process reduces tensile stresses within the coating. To provide quantitatively comparison to the com- putational results, hole-drilling method was used to evaluate the residual stresses. The measured residual stresses are in agreement with the numerical simulation results obtained from FEA.