Surface Morphology and Roughness Characterization of Laser Textured TC4 Titanium Alloy
X. Chen, F. Wang, C-X. Di, C-S. Zhang, Y-L. Bao, M. Tian and K. Luo
To explore the relationship of morphology and surface roughness on laser textured TC4 titanium alloy, both the process experiment and the numerical simulation approaches were adopted. The physical model of laser texturing pit was established under the condition of single pulse energy of 100, 150 and 200 mJ laser pulses irradiation using the COMSOL Multiphysics software, and the physical process of laser texturing was analysed, which laid a theoretical foundation for subsequent process experiments. A laser diode pumped Nd:YAG laser texturing experimental setup was build up. The process parameters, which are laser pulse energy, pulse width and defocusing amount included, were investigated with the monofactor analysis method. The roughness of laser texturing surface was measured from 0.71 to 13.86 μm, and the effects of these processing parameters on the surface roughness and pits morphology were analysed. Based on the morphological parameters, a mathematical integration algorithm for roughness was designed to simulate the laser texturing surface roughness, and the relationship between pit morphology and surface roughness was built up. After compared the calculated values with experimental results, it was proved that the algorithm can effectively reflect the surface roughness of samples. The experimental results show the guiding significance for the high-quality engineering application of laser texturing on titanium alloys.
Keywords: Nd:YAG laser, TC4 titanium alloy, laser texturing, pit morphology, surface roughness, numerical simulation