A Study on Hydrodynamics of Melt Expulsion in Pulsed Nd: YAG Laser Drilling of Titanium

S. Sharma [1], Y. Pachuary [2], S. N. Akhtar [3], J. Ramkumar [1],
[1] Indian Institute of Technology Kanpur, Kanpur, India
[2] Indian Institute of Information Technology, Design and Manufacturing, Jabalpur, India
[3] Integral University, Lucknow, India
Veröffentlicht in 2015

Laser drilling of titanium and its alloys is widely used in aerospace industry, as it offers selective removal of material at high accuracy and speed. However, laser drilling often inherits defects such as large heat affected zone, micro cracks and recast layer. These defects depend upon complex melting and solidification phenomena happening due to interaction of high-intensity laser with the material. Therefore, to understand and control these processes, a multi-phase (solid, liquid, and vapor) axisymmetric model is computed using COMSOL Multiphysics®. Moving mesh interface is used to simulate the melt displacement based on the physical processes involved. The model also studies effects of different laser intensity profiles (ideal Gaussian profile and top-hat profile) on temperature distribution, melt velocity and the shape of the keyhole.