激光熔覆Ni/WC涂层温度场及形貌模拟

Simulation of temperature field and morphology of laser cladding Ni/WC coating

根据同轴送粉激光熔覆的特点,利用有限元软件ANSYS模拟温度场的动态过程,采用生死单元法求得熔覆层形貌的三维模型,模拟中加入了熔覆粉末的温升、激光的衰减、相变潜热以及温度对材料热物理性能的影响等因素的影响作用,并且对温度场的结果进行了分析和试验验证。结果表明,熔池前方温度梯度比后方大,熔池最高温度在短时间之后会基本保持稳定。在高锰钢表面采用4000 W多模光纤激光器熔覆镍包WC复合粉末,涂层组织主要为细化树枝晶,通过对熔覆层横截面形貌、组织形貌、温度场分布的观察分析,验证了模拟结果的准确性,可作为制备涂层的工艺的理论参考。

According to the characteristics of coaial powder laser cladding,the dynamic process of temperature field was simulated by using the finite element software ANSYS,and three-dimensional model of cladding morphology was obtained by life-death method.The influence factors such as the attenuation of laser energy,the temperature rise of powder particles,latent heat of phase change and temperature on thermal physical properties were analyzed in the model,and the results of the temperature field were analyzed and verified.The results show that the temperature gradi-ent in front of the molten pool is larger than that of the back molten pool,and the maimum temperature of the molten pool will remain stable after a short time.Ni-based WC composite powders were deposited on the high manganese steel surface using 4000 W multimode fiber laser.The microstructure of Ni60A coating is mainly refined dendrite.Through the observation and analysis of the cross-section morphology,microstructure and temperature distribution of the clad-ding layer,the accuracy of the simulation results is verified.It provides a theoretical reference for the preparation process of coating.