ZrO2／Ni阶梯热障涂层的热冲击行为

研究了ＺｒＯ２／Ｎｉ阶梯热障涂层在火焰喷烧和水淬炳途中热冲击条件下的失效行为，建立了梯度热障涂层在火焰喷烧和水淬热冲击条件下一维温度场应力场的解析模型，实验结果表明，涂层的抗热冲击能力在火焰喷烧条件下随层次折增加而增强，在水淬热冲击条件下却随层次的增加而降低，证实涂层的抗热冲击能力与热冲击条件有关，并取地表面换热系数的大小与方向，故评价涂层的抗热冲击能力时须合理选择热冲击条件，按梯度设计，能大大提

THERMAL SHOCK BEHAVIOR OF ZrO_2/Ni GRADED THERMAL BARRIER COATINGS

The failure behaviors of ZrO2/Ni graded thermal barrier coatings under the conditions of thermal shock with fiame jet and water quenching have been studied. The one-dimensi-onal analytic model of temperature and stress field under these conditions for the coatings hasbeen established. The thermal shock resistance of coatings increases with the increase of layersunder the condition of fiame jet and decreases with the increase of layers under the condition ofwater quenching, which can be reasonably explained with the present model. The thermal shockresistance depends on the thermal shock conditions, and is determined by the magnitude anddirection of the surface heat exchange coefficiellt. Therefore, it is necessary to choose suitablethermal shock condition to evaluate the ability to resist shock of coatings. For thermal barriercoatings which are applied to the turbine blade of aeroengine or under the matchable thermalshock conditions, gradient structure mny sigIilficantly improve their ability to resist thermal shock.