Ultra-short pulsed laser conditioning of metallic-bonded diamond grinding tools

Abstract

A novel approach for machining of cylindrical ultra-hard materials with a highly defined contour is presented. Diamond grinding tools with complex geometry are manufactured with picosecond orthogonal and quasi-tangential laser ablation. Hitherto, laser manufacturing required a special axis configuration and optical beam deflection devices are utilized. Here, strategies and processes on a scanhead-free configuration using ultra-short pulsed laser are discussed enabling straight-forward implementation in industry. This rapid and flexible approach for the production of master tools for industrial grinding processes reveals benefits compared to conventional techniques. The manufacturing time is comparable to standard processes, however, increased grain protrusion is attained with the presented laser sharpening strategy. An ablation study for maximal material-removal rate reveals the impact of wavelength, strategy, and repetition rate at high average power up to 100 W. A combined laser manufacturing routine enables an ablation rate of 35 mm3 min−1 and a maximal geometric deviation of 3 μm after finishing. The final grinding tools are sharpened by a radial laser process preferentially removing the metal-based binding material. Hence, high-precision diamond grinding wheels with a mean error of smaller 1 μm over millimeter-sized contours can be manufactured. The meta-stable diamond structure persists and is assessed via Raman spectroscopy studies at laser cut grains.