Grain wear properties and grinding performance of porous diamond grinding wheels

Abstract

Conventional diamond grinding wheels present challenges such as poor self-sharpening and difficulties in achieving ductile domain machining when processing hard and brittle materials, reducing machining quality and efficiency. This paper introduces a novel grinding wheel composed of porous diamond abrasive grains for better ultra-precision machining. Thermochemical etching is used to produce porous diamond grains of varying corrosion levels, and the cutting and wear mechanisms of these grains are investigated through molecular dynamics simulations and single-grain scratch tests. Compared to conventional diamond grains, the increased "micro-edge" and "multi-edge" features of porous diamond grains effectively reduce cutting force and heat. Notably, corrosion pore sizes ranging from 2 μm to 5 μm reduce cutting damage. Conventional diamond abrasive grains primarily incur damage through crystal surface dissociation and block crushing, whereas porous diamond abrasive grains experience damage mainly due to micro-crushing and micro-fracture. Ultra-precision grinding tests on 4H–SiC revealed that conventional abrasives produced cracks and pits on the grinding surface. In contrast, abrasives with a 2 μm eroded aperture exhibited predominantly ductile removal with minimal cracks and pits present. Abrasives with a 5 μm eroded aperture displayed desirable characteristics. This research offers valuable technical insights for enhancing the grinding performance of diamond wheels.