预热对激光熔覆陶瓷涂层温度场和应力场影响

发布时间：2018-08-07 21:02

【摘要】：采用SYSWELD软件建立激光熔覆Ni-WC-Cr3C2涂层的热应力分析的有限元模型,通过熔池形貌对比验证模型的可靠性。利用建立的模型,进一步分析陶瓷涂层冷却阶段温度梯度和应力场的变化规律及基板预热对温度梯度和应力分布的影响。结果表明,激光熔覆处理是经历了快速加热、快速冷却的过程,陶瓷涂层内呈拉应力状态,极易沿垂直扫描方向发生脆性开裂。基板预热可以显著降低陶瓷涂层的冷却速度,且预热温度越高,冷却速度降低越明显,涂层内应力也随之降低。预热350℃及以上可以有效抑制裂纹产生。
[Abstract]:The finite element model of thermal stress analysis of laser cladding Ni-WC-Cr3C2 coating was established by SYSWELD software. The reliability of the model was verified by comparing the morphology of molten pool. By using the established model, the variation of temperature gradient and stress field in the cooling stage of ceramic coating and the effect of substrate preheating on temperature gradient and stress distribution were analyzed. The results show that the laser cladding process goes through the process of rapid heating and rapid cooling, and the ceramic coating exhibits tensile stress state, and brittleness cracking easily occurs along the vertical scanning direction. Substrate preheating can significantly reduce the cooling rate of ceramic coating, and the higher the preheating temperature, the lower the cooling rate and the lower the internal stress of the coating. Preheating at 350 鈩，

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