Formation mechanism of recast layer in millisecond laser drilling of Ti6Al4V alloys

被引：1
作者：
Zhang T. [1 ,2 ]
Zhang C. [1 ]
Li J. [2 ]
Zhang H. [1 ]
Lu J. [1 ]
机构：
[1] School of Science, Nanjing University of Science & Technology, Nanjing, 210094, Jiangsu
[2] College of Mechanical and Electrical Engineering, ZhouKou Normal University, Zhoukou, 466001, Henan
来源：
Zhang, Hongchao (hongchao163@163.com) | 1600年 / Chinese Optical Society卷 / 37期
关键词：
Laser drilling; Laser technique; Level-Set method; Millisecond laser; Recast layer; Ti6Al4V alloy;
D O I：
10.3788/AOS201737.0214001
中图分类号：
学科分类号：
摘要：
During the process of millisecond laser drilling of Ti6Al4V alloys, the recast layer forms along hole walls, which is a serious detriment to hole quality. In consideration of the thermal and mechanical parameters influencing melt and based on the modified equations of fluid mechanics and improved Level-Set method, a solid/liquid/gas three-phase two dimensional numerical model is constructed used for laser drilling. The numerical investigation of laser drilling with different pulse widths and with single pulse energy of 3 J is conducted. The temperature field, flow field, and thickness distribution of recast layer during the drilling process are obtained by using the post-processing technology. The results indicate that molten liquid is discharged mainly by means of evaporation and ejection and the recast layer is formed under the coupling effect of heat and force. The recast layer thickness increases with the increment of laser pulse width, which possesses a characteristic of recast layer becoming thin slowly from top hole to bottom hole. © 2017, Chinese Lasers Press. All right reserved.
引用
收藏
页数：10
相关论文
共 24 条
  • [1] Zhao S., Li L., Numerical investigation of phase change during thermal ablation of gold films induced by femtosecond laser, Acta Optica Sinica, 35, 12, (2015)
  • [2] Leigh S., Sezer K., Li L., Et al., Statistical analysis of recast formation in laser drilled acute blind holes in CMSX-4 nickel superalloy, International Journal of Advanced Manufacturing Technology, 43, 11-12, pp. 1094-1105, (2009)
  • [3] Zhang T.Z., Jia Z.C., Cui H.C., Et al., Analysis of melt ejection during long pulsed laser drilling, Chinese Physics B, 25, 5, (2016)
  • [4] Voisey K.T., Klocker T., Clyne T.W., Measurement of melt ejection velocities during laser drilling of steel, using a novel droplet stream interception technique, Acta Materialia, 50, 17, pp. 4219-4230, (2002)
  • [5] Low D.K.Y., Li L., Byrd P.J., Spatter prevention during the laser drilling of selected aerospace materials, Journal of Materials Processing Technology, 139, 1-3, pp. 71-76, (2003)
  • [6] Duan W.Q., Wang K.D., Dong X., Et al., Experimental characterizations of burr deposition in Nd∶YAG laser drilling: A parametric study, International Journal of Advanced Manufacturing Technology, 76, 9-12, pp. 1529-1542, (2015)
  • [7] Yilbas B.S., Karatas C., Uslan, Et al., CO<sub>2</sub> laser gas assisted nitriding of Ti-6Al-4V alloy, Applied Surface Science, 252, 24, pp. 8557-8564, (2006)
  • [8] Yilbas B.S., Sami M., Liquid ejection and possible nucleate boiling mechanisms in relation to the laser drilling process, Journal of Physics D-Applied Physics, 30, 14, pp. 1996-2005, (1997)
  • [9] Yang C.J., Mei X.S., Wang W.J., Et al., Recast layer removal using ultrafast laser in titanium alloy, International Journal of Advanced Manufacturing Technology, 68, 9-12, pp. 2321-2327, (2013)
  • [10] Duan W.Q., Dong X., Wang K.D., Et al., Effect of temporally modulated pulse on reducing recast layer in laser drilling, The International Journal of Advacned Manufacturing Technology, 87, 5, pp. 1641-1652, (2016)
123