强度空间分布对脉冲激光表面强化的影响  

Influence of Spatial Intensity Distribution on Pulsed Laser Surface Hardening

作　　者：吴炜[1] 梁乃刚[1] 甘翠华[2] 虞钢[2] 

机构地区：[1]中国科学院力学研究所非线性力学国家重点实验室,北京100080 [2]中国科学院力学研究所技术发展部,北京100080

出　　处：《金属热处理》2005年第10期30-35,共6页Heat Treatment of Metals

基　　金：国家自然科学基金(10232050);国家973项目(2002CB412706)

摘　　要：建立了包含脉冲激光强度时空分布、温度相关的材料热物性参数以及多次相变特征在内的脉冲激光表面强化三维有限元模型。温度场和强化区深度分别得到了解析解和试验验证。针对不同脉冲能量级别,研究了强度空间分布形式和光斑几何形状对表面最高温度、强化区深度以及强化区形状等的影响。结果表明,激光强度空间分布是影响强化区的重要因素。为达到理想的强化效果,应根据不同的脉冲能量选择适当的空间分布形式和光斑几何形状。A 3D finite element model for simulating pulsed laser transformation hardening was established ,in which laser spatial and time-dependent intensity distribution, temperature-dependent thermophysical properties of material, microstructural evolution and multi-phase transformations were covered. Temperature field and its evolution obtained from this model were validated with analytical method, and the predicted hardening depth is verified with experimental one, respectively. The influences of laser intensity distribution form and geometric pattern of laser spot on maximum surface temperature, hardening depth and connectivity of hardened zone were investigated at different pulse energy levels. The results show that the laser spatial intensity distribution is a critical factor to influence hardening zone. It should be pointed out that appropriate laser intensity distribution form and geometric pattern should be selected according to pulse energy level in order to achieve desirable hardening quality.

关 键 词：脉冲激光表面强化 数值模拟 强度分布 

分 类 号：TG156.99[金属学及工艺—热处理] O242.72[金属学及工艺—金属学]