激光辐照铝材表面温度场特征演化的数值模拟

Numerical simulation of characteristics evolution of aluminum surface temperature field irradiated by laser

建立激光辐照铝材料的有限元分析模型,对材料表面的温度场进行数值模拟。研究了激光光束在对材料表面扫描过程中激光扫描速度、TEM00及TEM1 0两种理想模式的叠加比例η的取值、材料厚度等因素对扫描结果的影响。分析了在材料上所取的几个目标点的温度场变化情况。仿真结果表明扫描的速度快慢决定了材料表面可以吸收激光能量的多少,影响材料的最高温度;η的取值决定了激光光束的能量分布情况,η值越高激光光束能量越集中,在扫描过程中目标点的温度变化越剧烈;随着深度的增加,材料内部的温度的最高值逐渐降低,温度的升高趋势逐渐趋于平缓。

A finite element model of aluminum by laser irradiation was created by the COMSOL software, and the tem- perature field distribution of aluminum surface was numerically simulated. The influence of laser scanning speed,the val- ue of superposition ratio 7/of two kinds of ideal models of TEMco and TEMI0 and material thickness on the transient tem- perature field of the material surface was discussed. The distribution and variation of temperature field of several points on the material were analyzed. These numerical simulation resuhs show that with the increase of laser scanning speed, the energy absorbed by the material and the highest temperature of the material decreases. The value of 7/determines the energy distribution of the laser beam. With the increase of η,the energy density of laser beam concentrates increasingly and temperature variation of these points on the material in laser scanning is very large. With the increase of depth,the highest value of the internal temperature gradually decreases, and the temperature variation becomes flat gradually.