中国激光, 2019, 46 (7): 0702002, 网络出版: 2019-07-11
激光抛光H13模具钢自由表面演变的数值模拟与验证 下载: 1360次
Numerical Simulation and Verification of Free-Surface Evolution in Laser Polishing of H13 Tool Steel
激光技术 激光抛光 数值模拟 频谱分析 毛细力 热毛细力 laser technique laser polishing numerical simulation spectrum analysis capillary force thermocapillary force
摘要
采用数值模拟与实验相结合的方法,通过建立激光抛光的二维瞬态模型,模拟了激光抛光过程中材料表面形貌的演变过程。在模拟过程中,采用移动激光束作为热源,通过对实际材料自由表面进行频谱分析,构建了相似的模拟模型表面,耦合激光抛光过程中的流动场和温度场,综合考虑毛细力和热毛细力的共同作用。结果表明:在毛细力和热毛细力的作用下,在被抛光的材料表面,波峰材料流向波谷,填补轮廓凹陷处,使得材料表面达到抛光效果。激光功率和扫描速度会显著影响抛光效果,过小的热输入会导致熔池尺寸过小,没有足够的流动体积,抛光效果差;过大的热输入则会导致熔池持续时间长,增大抛光表面的粗糙度。模拟的表面粗糙度、熔池深度与实验结果相比,误差均在8%以内,具有较高的模拟精度。
Abstract
Via numerical simulation and experiment, a two-dimensional transient model of laser polishing (LP) is established to simulate the surface-morphological evolution of materials during LP. A moving laser-beam heat source with the combined effects of capillary and thermocapillary forces is adopted, and the flow and temperature fields are also coupled. The simulated-model surface and the actual examined material surface are constructed by performing spectrum analysis. The simulated results show that under the effects of capillary and thermocapillary forces, the peak material flows to the trough and fills the contour hollow on the polished material surface, achieving the polishing effect. The laser power and scanning speed significantly affect the polishing results. A low-heat input leads to a small molten pool, resulting in a poor polishing effect with insufficient flow time; excessive heat input results in a molten pool with a long duration of time, which increases the LP surface roughness. Compared with the experimental results, the simulated surface roughness and the depth of the molten pool have an error of less than 8%, reaching a high simulation accuracy.
张伟康, 戴伟, 郑志镇, 李建军, 邓湉湉. 激光抛光H13模具钢自由表面演变的数值模拟与验证[J]. 中国激光, 2019, 46(7): 0702002. Weikang Zhang, Wei Dai, Zhizhen Zheng, Jianjun Li, Tiantian Deng. Numerical Simulation and Verification of Free-Surface Evolution in Laser Polishing of H13 Tool Steel[J]. Chinese Journal of Lasers, 2019, 46(7): 0702002.