送粉激光熔覆过程中熔覆轨迹及流场与温度场的数值模拟  

Numerical Simulation on Cladding Track,Fluid Flow Field and Temperature Field in Laser Cladding Process with Powder Feeding

作　　者：黄延禄[1] 邹德宁[1] 梁工英[1] 苏俊义[1] 

机构地区：[1]西安交通大学,陕西西安710049

出　　处：《稀有金属材料与工程》2003年第5期330-334,共5页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(59871038);西安交通大学科研基金;华中科技大学激光技术国家重点实验室基金资助

摘　　要：提出了一种送粉激光熔覆中熔覆层表面形状及厚度的计算模型。将熔覆过程中固相区、两相区和液相区作为一连续介质,用非稳态固液相变统一模型来描述其流场与温度场,并采用固定网格移动坐标来处理带移动热源的流动与传热问题。能量方程用显焓表示,有关潜热的非稳态项与对流项均做为其源项处理。用Lambert-Beer定理和米氏理论计算粉末流与激光光束的相互作用,使模拟适用于送粉浓度较大的情形。数值模拟程序是在流体动力学软件PHOENICS基础上,通过添加源项、边界条件、熔覆层轨迹计算以及激光束和粉末流相互作用等相应模块实现。对钢基底上熔覆钴基合金Stellite6进行模拟所得到的计算结果与实验结果基本一致。A computational model for determining the configuration and thickness of cladding layer was presented. Liquid, mushy and solid regions in laser cladding process were considered as a continuum, and the continuum model for binary solid - liquid phase change system was used to simulate the velocity and temperature fields, and a fixed - grid and moving coordinate system were adopted to deal with fluid flow and heat transfer problem involving moving heat source. The sensible enthalpy was used as a dependent variable in energy equation, and the terms including latent heat were merged into source term. Based on Lambert - Beer equation and Mie's theory, the interaction between powder stream and laser beam was treated to fulfil the situation of high powder concentration. The commercial software PHOENICS, to which several modules related with source terms, boundary conditions, interaction between powder stream and laser beam and configuration of cladding layer were appended, was used to accomplish the simulation. The results obtained by the simulation are coincident with those measured in experiment basically.

关 键 词：送粉 激光熔覆 数值模拟 熔覆轨迹 温度场 

分 类 号：TG174.4[金属学及工艺—金属表面处理]