Effect of fabrication parameters on grinding performances of electroplated Ni-B-diamond tools with D150-diamond particles

Electroplated Ni-B-diamond tools with D-150 diamond particles were fabricated and their tool life performances from slot grinding Al₂O₃ plates were evaluated. Electroplated diamond tools with high diamond particle density were prepared from martensitic stainless steel (AISI 440C) rods, using three sequential electroplating processes, namely Ni-undercoating, Ni-diamond co-electrodeposition, and Ni-B strengthening electroplating. Fabricating parameters of electroplated diamond tools, including the Ni-undercoating thickness, the choice between Ni-diamond and Ni-B-diamond co-electrodeposition, the diamond-coverage percentage, and the post-process annealing temperature, were studied to acquire the determinants of electroplated diamond tool with high grinding performance. Experimental results showed that the grinding performance of an electroplated diamond tool depends strongly on the Ni-undercoating thickness. The highest grinding performance can be achieved from the 400 °C-annealed electroplated diamond tool with Ni-undercoat thickness of 90 μm and diamond-coverage percentage of 80 %. Due to the cracking found along the interface between the Ni-undercoating and Ni-B deposit, Ni-B-diamond co-electrodeposition process is ill-suited for electroplated diamond tool fabrications. Diamond particles should extrude from the tool surface to cut and remove Al₂O₃ chips formed during grinding. Diamond-coverage should be more than 50 % to avoid low grinding performances due to the low bonding strength of diamonds.