等离子熔射成形熔滴薄片沉积的模拟研究

采用等离子熔射成形技术制造的模具和零件,其涂层的性能受残余热应力的影响极大。为此建立了一个二维有限元模型,用于研究单个不锈钢熔滴薄片在碳钢基体上沉积时的温度场及残余热应力。结果显示,尽管在初始的凝固阶段薄片边缘的温度高于薄片中心的温度,但随后这两个位置的温度差却发生逆转。最大残余应力位于薄片与基体界面的边缘,且其大小随基体温度升高而减小,最小残余热应力则位于薄片上表面的边缘。残余热应力在薄片中表现为拉应力,而在基体中则表现为压应力。本研究可为在微观水平上理解等离子熔射成形的温度场和残余热应力分布提供基础。

Simulation analysis of lamina deposition in plasma spray forming

The performance of the coatings manufactured by plasma spray forming technology is significantly influenced by the residual stresses.It is,therefore,necessary to investigate the temperature history and residual stress distribution of the lamina,which is the basic constructing element of the coating.A 2D finite element model constructed for temperature and residual stress simulation of a single stainless steel lamina solidifying and cooling on the carbon steel substrate was presented.The results show that the temperature of the lamina edge is higher than that of the central area during the initial solidification,and the temperature difference between the two areas reverse thereafter.The maximum residual stress,which decreases when the substrate is preheated to a higher temperature,situates at the edge of the interface,and the minimum residual stress locates at the edge of the top surface of the lamina.The residual stresses appear as tensile stresses within the lamina and compressive stresses within the substrate.The research can provide quantitative understanding of the temperature and residual stress states on the microcosmic scale.