不同基底上等离子喷涂钼层片形成过程的三维模拟

摘要

基于有限体积法，运用流体体积法(VOF)追踪自由液面，同时考虑流动、传热和基底熔化的耦合，对在1Cr13不锈钢和 H70黄铜基底上等离子喷涂钼层片的形成过程进行了三维瞬态模拟；通过等离子喷涂试验制备了钼层片，利用扫描电子显微镜和台阶仪分别测试了钼层片的形貌和表面轮廓曲线，并将试验结果与模拟结果进行了对比验证。结果表明：在两种基底上模拟得到的钼层片形貌、厚度、铺展系数以及基底撞击凹坑深度都与试验结果吻合较好；1Cr13不锈钢基底上钼层片发生飞溅是由于钼熔滴在铺展过程中受到已凝固薄层的阻碍而抬离基底，进而脱离已凝固层而形成的。%The formation of plasma sprayed molybdenum splats on 1Cr13 stainless steel and H70 brass substrate was simulated by three dimensional transient modeling based on the finite volume method,using the volume of fluid method (VOF)to track the free surface of droplet and considering the flow coupled with heat transfer and substrate melting.The molybdenum splats were prepared on the substrates by plasma spraying and the morphology and profile curves of the splats were tested by scanning electron microscope and step profiler respectively.The experimental results were compared with those of simulation.The results show that the morphology,thickness,spreading factor of splats and substrate crater depth obtained from modeling agreed well with experimental results.The spreading periphery of molybdenum droplet was lifted over the 1Cr13 steel substrate due to the obstacle of solidified layer,and then the periphery separated from the solidified layer and formed the splashing of molybdenum droplet on 1Cr13 stainless steel.