脉冲激光钼表面氮化处理温度场的数值模拟

Numerical Simulation for Temperature Field of Laser Gas Alloying on Molybdenum Surface

本文用有限差分法对金属钼表面脉冲激光生成氮化用薄膜过程的温度场进行了三维数值模拟计算．计算模型在能量平衡方程的基础上，将入射的脉冲激光在时间与空间上的分布以Ｇａｕｓｓ分布考虑，同时考虑工件尺寸、工件材料热物理性质及对流辐射造成的表面热损失等对温度场的影响．此外还从理论上计算了激光脉冲在脉冲宽度加宽后的温度场变化，分析了利用长脉冲激光进行材料表面相变硬化和激光重熔的可行性．

In this papers numerical simulation for temperature field of Mo2N films generated on molybdenum surface using laser gas alloying(LGA) method is performed by finite-difference method. The numerical model used takes into account of Gauss distribution' in space and time' of laser spot, the finite size of sample, the temperature dependence of themophysical properties, and the surface heat losses due to convection and radiation. The changes of temperature field are calculated accordingly. The feasibility of using pulse laser for laser surface transformation hardening and laser surface remelting is also analyzed.