Tangential dressing of diamond grinding wheel by femto-second pulsed laser with Bessel beam

Abstract

Bronze bonded diamond grinding wheel is widely used in grinding hard and brittle materials. In order to improve the profile accuracy of the grinding wheel, an ultra-fast laser dressing method with Bessel beam for diamond grinding wheel is proposed in this study. The coarse grain (100 #) bronze bonded diamond grinding wheel is tangentially shaped by laser dressing. By comparing the profile and surface quality of the grinding wheel dressed with Gaussian laser beam and Bessel laser beam under different defocusing amounts, it is found that Bessel beam can dress the grinding wheel in the focal depth of 1.2 mm, which is three times of traditional Gaussian beam. The ablation thresholds of bronze binder and diamond under Bessel beam are obtained through experiments and theoretical calculations. The results show that when the laser power density is 3.75 × 105 W/cm2 – 4.75 × 105 W/cm2 and the axial scanning speed of the laser is 0.03 mm/min, the diamond grit has an enough protrusion height, and the runout of the grinding wheel is reduced to about 6 μm. When the wheel speed is too low, it will reduce the overlap rate of axial scanning trajectory and reduce the removal efficiency of material.