等离子喷涂Sm_2Zr_2O_7/8YSZ热障涂层热冲击应力的数值模拟  

Numerical Simulation of Thermal Shocking Stress of Plasma-Sprayed Sm_2Zr_2O_7/8YSZ Thermal Barrier Coating

作　　者：张红松[1] 李世显[2] 

机构地区：[1]河南工程学院机械工程系,河南郑州451191 [2]郑州铁路职业技术学院机电工程系,河南郑州450052

出　　处：《材料保护》2013年第7期25-28,6,共4页Materials Protection

摘　　要：热障涂层的热冲击应力对其热冲击性能有重要影响,有关其热冲击应力的研究鲜见报道。采用有限单元法研究了基体材质、厚度对等离子喷涂Sm2Zr2O7/8YSZ热障涂层水淬热冲击应力的影响,并与8YSZ涂层比较。结果表明:涂层内存在较大径向冲击热应力,其值随基体热膨胀系数增加而增大;随基体厚度增加,径向应力逐渐增加,厚度超过25 mm后对径向应力无影响;剪切压应力的绝对值随基体厚度增加而增大,基体厚度超过20 mm后趋于稳定;基体厚度对轴向应力无影响;该涂层的抗热冲击性能优于传统8YSZ涂层。The effects of thermal expansion coefficient and thickness of substrates on water-quenching thermal-shocking behavior of plasma-sprayed Sm_2Zr_2O_7-zirconia stabilized by 8%yitria thermal barrier coating(denoted as Sm_2Zr_2O_7/8YSZ) were studied by finite element method,and comparative study with conventional 8YSZ coating was also conducted.Results showed that there was relatively high radial thermal-shocking stress in as-prepared Sm_2 Zr_2 O_7/8YSZ thermal barrier coating.The radial thermal shocking stress of Sm_2Zr_20_7/8YSZ thermal barrier coating tended to gradually increase with increasing thermal expansion coefficient and thickness of substrates,but it keeped unchanged when the thickness of the substrates was above 25mm.In the meantime, the absolute values of shear stress of Sm_2Zr_20_7/8YSZ thermal barrier coating tended to gradually rise with increasing thickness of the substrates,but it keeped almost unchanged when the thickness of the substrates was above 20 mm.Moreover,the thickness of substrates had no influence on the axial thermal stress of Sm_2Zr_2O7/8YSZ thermal barrier coating.Sm_2 Zr_2 O_7/8YSZ thermal barrier coating had much better thermal-shocking behavior than conventional 8YSZ coating.

关 键 词：Sm2Zr2O7 8YSZ热障涂层 热冲击应力 数值模拟 等离子喷涂 基体材质 基体厚度 

分 类 号：TG174.442[金属学及工艺—金属表面处理]