Investigation of the Laser Processing Mechanism of Tooth-Surface Texturing in PEEK-Based Involute Splines

Abstract

To reveal the response behavior and formation mechanism of femtosecond laser-induced microtextures on the tooth surfaces of PEEK-based involute splines, this study selected three materials, namely PEEK5600G, PEEK5600LF30, and PEEK5600CF30. An orthogonal experimental design was adopted to systematically investigate the effects of laser average power, scanning speed, and number of scans on texture depth and width. The processed surfaces were characterized in terms of three-dimensional morphology using a DSX510 digital microscope. The experimental data were further processed, verified, and statistically analyzed using MATLAB and Origin. The results showed that the texture depth of all three materials was mainly governed by laser power. However, the three materials exhibited different response characteristics. For PEEK5600G, the texture depth was significantly affected by both laser power and scanning speed. For PEEK5600CF30, the texture depth was mainly controlled by laser power. In contrast, PEEK5600LF30 showed high sensitivity to laser power, scanning speed, and number of scans. The variation in texture width showed clear material dependence. For PEEK5600G, the texture width was mainly affected by laser power. For PEEK5600CF30, it was mainly influenced by scanning speed and number of scans. PEEK5600LF30 was sensitive to all three factors. Meanwhile, microscopic morphology analysis further showed that all three PEEK-based materials exhibited a competing material removal mechanism of ablation and melting under femtosecond laser irradiation. Ablation dominated in the central region of the groove, whereas a recast layer and molten material accumulation tended to form at the edges. Differences in the reinforcing components led to different thermophysical response characteristics, which ultimately resulted in significant differences in groove profile, edge quality, and parameter sensitivity.