Effects of novel rotary-abrasive finishing pad textures on the controlled 2-body abrasive wear of Type 304 stainless steel

Abstract

Recently abrasive tools can be manufactured with precision cutting features of defined grit geometry, size and spacing. This paper investigates the rotary-abrasive finishing performance of engineered abrasive tools with different grit geometries (i.e. square frustum, saw tooth) employed in planetary grinding process, and comparisons are made between these engineered abrasive tools with conventional abrasive tools from the point of view of wear of abrasive edges and surface quality. Scanning Electron Microscopy (SEM) supported by surface morphological investigations enabled the understanding of the interaction mechanisms between conventional/engineered abrasive grits and workpiece surface allowing the definition of key design parameters of the engineered grinding pads. The research proved that the engineered abrasive grits with symmetric shape (e.g. square frustum) can generate better surface roughness (0.188μm) than that of both engineered abrasive grits with asymmetric shape (e.g. saw tooth, 0.298μm) and conventional abrasive grits (0.488μm) after certain amount of grinding time (5min, sliding distance 180m). Moreover, symmetric abrasive grits with lower grit density (30 grits/pellet) tend to have a higher removal rate than that with higher grit density (200 grits/pellet), hence it is more beneficial to be employed. The main wear mechanisms for conventional abrasive grits are microfracture, flattening and cracking, while only some few microfracture can be observed for engineered abrasive grits due to its compact columnar structure. Plastic deformation is the predominant removal mechanism on the workpiece surface for both conventional and engineered abrasive grits; however, the conventional grits exhibited more (e.g. twice the level) plucking than that of engineered abrasive grits.