Mass Fabrication of Microholes in Aviation Kerosene Filters Using the Back-water-assisted Picosecond Laser Drilling Technique
X-S. Zhang, Z-Y. Zhang, H. Zhu, S-W. Li, Y-F. Wang, K. Xu, S-L. Chu and J-J Huang
Laser drilling is an emerging non-traditional machining method suitable for mass micron-sized hole fabrication in stainless steel aviation filters; however, the thermal deformation of the filter directly processed by laser is serious, and the taper and roundness of the filter hole are poor. A back-water-assisted laser processing method is proposed in this study, in which benefits can be achieved in reducing hole taper and improving hole roundness and consistency. The results show that, compared with direct laser drilling, the back-water-assisted method can reduce the taper by up to 6 , while increase the processing efficiency by 40 to 60%. The slag, recast layer of the hole walls and the deformation of the filter are also reduced significantly. In particular, this study proposes a method to assess the consistency of mass holes, and the influencing degree of each parameter on the consistency of microholes is obtained through orthogonal experiments.
Keywords: Nd:YVO4 laser, picosecond laser, stainless steel, aviation kerosene filter, laser drilling, back-water-assisted laser processing, mass microholes, hole consistency