Author Affiliations
Abstract
1 School of Science, Nanjing University of Science & Technology, Nanjing 210094, China
2 Institute of Mechanical and Electrical Engineering, Zhoukou Normal University, Zhoukou 466000, China
The stress damage process of a single crystal silicon wafer under millisecond laser irradiation is studied by experiments and numerical simulations. The formation process of low-quality surface is monitored in real-time. Stress damage can be observed both in laser-on and -off periods. Plastic deformation is responsible for the first stress damage in the laser-on period. The second stress damage in the laser-off period is a combination of plastic deformation and fracture, where the fundamental cause lies in the residual molten silicon in the ablation hole.
140.3330 Laser damage 140.3390 Laser materials processing Chinese Optics Letters
2018, 16(1): 011404
1 南京理工大学理学院， 江苏 南京 210094
2 周口师范学院机械与电气工程学院， 河南 周口 466001
Ti6Al4V合金在毫秒激光打孔过程中，沿孔壁会形成严重影响成品性能的重铸层。考虑熔体受到的热学和力学等方面的影响，基于修改的流体力学方程和改进的水平集法，建立了激光打孔的固/液/气三相二维数值计算模型，在单脉冲能量为3 J的条件下,对不同脉宽参数的激光打孔进行数值研究。运用后处理技术提取了打孔过程中重铸层的温度场、流场和厚度分布情况。结果表明，蒸发和喷溅是熔体排除的主要方式，重铸层是在热-力耦合作用下形成的。重铸层的厚度随激光脉宽的增大而增加，并呈现从孔口到孔底逐渐变薄的特征。
激光技术 激光打孔 重铸层 水平集法 Ti6Al4V合金 毫秒激光
Author Affiliations
Abstract
School of Science, Nanjing University of Science and Technology, Nanjing 210094, China
A two-dimensional, transient model is proposed to study the dynamic process of keyhole formation and the material changes during both the laser-on and -off periods. The keyhole shape, temperature field, and velocity field are analyzed. The results indicate that the dynamic changes of the target material in the laser-off period have a great influence on the final structure of the keyhole.
000.4430 Numerical approximation and analysis 140.3330 Laser damage 140.3390 Laser materials processing 160.3900 Metals Chinese Optics Letters
2015, 13(8): 081403
