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利用有限元方法,采用弹塑性理论对FeCrAl合金基陶瓷涂层中的应力场进行了数值模拟,得出了陶瓷涂层中应力σx(在x方向)、σy(在y方向)和τxy(x-y平面)的分布特征。研究表明在试样近边缘处涂层界面的残余拉应力σx和σy出现极大值,对于上部涂层分别为40和43.04MPa,对于侧面涂层分别为40.40和43.38MPa。涂层开裂或剥落最有可能从此处开启,然后在残余压应力σx(上部涂层)、σy(侧面涂层)和剪切应力τxy的作用下向试样中部涂层中扩展,从而导致涂层的保护功能失效。模拟结果与试样的抗热冲击试验获得较好吻合。
The stress field in the FeCrAl alloy based ceramic coating was numerically simulated by using the finite element method (FEM) and the stress σx (in the x direction), σy (in the y direction) and τxy (xy Plane) distribution characteristics. The results show that the maximum tensile residual stress σx and σy at the coating interface near the sample edge are 40 and 43.04 MPa for the top coating and 40.40 and 43.38 MPa for the side coating, respectively. The cracking or spalling of the coating is most likely to start from there and then expands into the middle coating of the sample under the effects of residual compressive stress σx (upper coating), σy (side coating) and shear stress τxy, Layer protection fails. The simulation results are in good agreement with the thermal shock tests of the specimens.