Wear mechanisms of diamond abrasives during transition and steady stages in creep-feed grinding of structural ceramics

A study was performed to quantify the wear mechanisms of diamond abrasives of a resin bonded diamond wheel (320 US mesh and 100 concentration) in creep-feed grinding of a silicon nitride material. This was achieved with a combined use of a lead-tape imprint technique and SEM. The wear mechanisms observed include attritious wear, fracture (or chipping), mixed mode of wear and fracture, and dislodgment (or pullout). The percentage of each wear mechanism was quantified for different points of the grinding process: five during the transition stage and six during the steady stage. The results indicate that: (1) the percentage of grits not involved in removing the first 10 cm3/cm volume of material per unit width was high (∼70%) and decreased as more material was removed (from −50% to 20% during the steady stage). (2) Attritious wear dominated the wear mechanism and the percentage increased as more material was removed (from ∼15% to 30% during the transition stage and from ∼50% to 75% during the steady stage). Correspondingly, the percentage of wear-flat area also increased. (3) The percentages of grit dislodgment and grit fracture were relatively higher during the transition stage than during the steady stage. (4) The number of active grits per unit area increased with cumulative volume of material removed. (5) Specific forces increase nonlinearly with wear-flat percentage and the percentage of worn grits.