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运用ANSYS有限元分析软件,对送粉式多道搭接激光熔覆过程的温度场进行了数值模拟。考虑到材料热物性的非线性特征以及对流换热的边界条件,建立了三维有限元模型;送粉过程及熔覆单元的生长过程采用“生死单元法”来实现。结果表明:在多道搭接激光熔覆过程中,先凝固的熔覆道对后续搭接熔覆道有预热作用,两者之间存在一个初始温度差;在熔覆层中,搭接区的温度高于其它区域,存在重熔现象;熔覆层每道熔池节点的热循环曲线呈现周期性变化且基本相似;熔覆层易出现端部效应问题;熔覆层中上部温度梯度沿激光扫面方向水平分布,下部与扫描方向垂直分布,在基体与熔覆层交界处温度梯度出现突变和最大值,是裂纹高发区。
ANSYS finite element analysis software was used to simulate the temperature field in the multi-lap laser cladding process. Considering the non-linear characteristics of the material’s thermophysical properties and the boundary conditions of convective heat transfer, a three-dimensional finite element model was established. The process of powder feeding and the growth of cladding units were implemented using the “unit of life and death method”. The results show that during the lap lapping process, the first solidified cladding lanes preheat the subsequent lap cladding lamella, and an initial temperature difference exists between them. In the lamella, The temperature of the zone is higher than that of other zones, and the remelting phenomenon exists. The thermal cycling curve of each weld pool in the cladding layer presents periodic changes and is basically similar; the end effect is easy to appear in the cladding layer; the temperature gradient in the upper part of the cladding layer Along the laser scanning direction horizontal distribution, the lower part of the vertical distribution of the scanning direction, the temperature gradient at the junction of the substrate and the cladding layer mutation and maximum, is the crack-prone areas.