Investigation of feed rate impact on microscale surface textures and turning performance of SiAlON ceramic cutting tools

Microscale textures inspired by nature were created on the rake face of SiAlON ceramic inserts using a femtosecond laser system. A detailed investigation was carried out to study the effect of laser parameters such as power, focal length, passing frequency, and media (air/water) on the inserts. The cutting performance of both the non-textured and textured SiAlON inserts was evaluated in terms of tool wear, chip-tool contact length, shear angle, and chip morphology during high-speed turning operations on INC-718. The optimization of laser parameters revealed that grooves were successfully formed in air, but water disrupted the laser focus, resulting in non-linear grooves. A detailed analysis of cutting insert wear patterns at different feed rates indicated the significant impact of texturing on the rake face. The application of surface texturing reduced crater wear, enhanced wear resistance, and minimized tool-chip contact, especially on the inserts with textured grooves located 100 mu m from the cutting edge. Examination of chip-tool contact length and chip flow angles on textured and non-textured inserts showed that surface texturing reduced contact length and facilitated gradual chip curling, resulting in a decrease in chip flow angles. Surface texturing also reduced chip thickness, increased shear angle, decreased burr formation, and changed chip morphology during high-speed machining of Inconel 718.