移动脉冲激光标刻Pb99.994的数值模拟与参数分析

Numerical Simulation and Parameter Analysis of Pb99.994 Marked by Moving Pulse Laser

针对移动纳秒脉冲激光控制参数对Pb99.994铅锭标刻区域温度分布影响规律尚不明确的情况,基于传热学理论,分别建立了光纤式脉冲激光单脉冲和连续脉冲标刻金属表面的三维非线性温度场通用模型,并通过单因素实验重点讨论了在单脉冲作用下不同水平的功率、频率和速度对温度的影响变化以及多脉冲条件下的累积效应。最后通过显微测量深度与模型计算深度对比,验证了模型的准确性。实验结果表明:单脉冲作用下,功率对材料温度升温幅度影响最大,功率由10 W升至18 W时,中心点温度升高幅度约为2 000℃;连续脉冲作用下,速度是脉冲累积效应变化的主因,脉冲累积效应对影响区域温度的提升不大,而对标刻灰度有一定程度上的决定关系,这为金属材料有效标识选择合适的工艺参数提供了参考依据。

For the case that the influence of moving nanosecond pulsed laser control parameters on the temperature distribution of the marking area of Pb99.994 lead ingots is not yet clear,general models of a three-dimensional nonlinear temperature field about the single-pulse and continuous pulse marking on metal surfaces with fiber-optic pulse lasers are established respectively on the basis of the theory of heat conduction.Then through single-factor experiments,it focuses on the effects of different levels of power,frequency,and velocity on the temperature under a single pulse and the cumulative effects under multi-pulse conditions.Finally,the accuracy of the model is verified by comparing the depth of microscopic measurement with the calculated depth of the model.The results show that power has the greatest effect on the temperature increase of the material temperature under the single pulse,when the power is increased from 10 W to 18 W,the temperature rise of the center point is about 2 000℃.Under the action of continuous pulse,the main cause of the cumulative effect of the pulse is the velocity.The cumulative effect of the pulse has little effect on the temperature of the affected area,but it has a certain degree of relationship with the marking gray level,which provides a reference for the selection of suitable process parameters for the effective identification of metal materials.