Grinding characteristics of ultrafine-grained wheels utilizing agglomerated ultrafine diamond abrasives

Agglomerated ultrafine diamond (AUD) abrasives were developed to enhance the grinding stability of ultrafine-grained wheels for hard-brittle materials. Grinding characteristics of AUD wheels utilizing AUD abrasives with a primary particle size of 2 μm were investigated. Average undeformed chip thickness models were established to correlate the grain size characteristics of AUD wheels with those of single-crystal diamond (SCD) wheels. Under conditions of comparable average undeformed chip thicknesses for the two wheel types and using fused silica as the workpiece material, a combination of molecular dynamics (MD) simulations, ball-on-disk friction tests, and precision grinding experiments was conducted. The models revealed that the average undeformed chip thickness of AUD wheels with a primary particle size of 2 μm and a secondary particle size of 40 μm is approximately equivalent to that of SCD wheels with particle sizes in the range of 6.6–10.2 μm. Simulations revealed that the multi-micro-edge cutting behavior of AUD abrasives offers significant advantages in reducing machining damage. In friction tests, the AUD ball maintained a higher and more stable coefficient of friction and exhibited greater material removal efficiency than the SCD ball under precision processing scenarios. Furthermore, the grinding experiments revealed significantly improved surface quality and enhanced processing stability with the AUD wheel. These advantages are attributed to the multi-micro-edge cutting behavior and the self-sharpening effect caused by the micro-fracturing of AUD abrasives. Therefore, AUD wheels provide a practical and effective solution for facilitating the application of ultrafine abrasives in the precision grinding of hard-brittle materials.