An acoustic emission analysis for evolution of material removal mechanisms in fixed abrasive lapping

<!-- START_ABSTRACT --> <p> This study investigates the evolution of material removal mechanisms during fixed abrasive (FA) lapping using acoustic emission (AE) analysis. The wavelet synchro-squeezing transform (WSST) and marginal spectrum analysis were employed to analyze AE signals collected during lapping with single crystal diamond (SCD), agglomerated diamond (AD), and non-abrasive pads. The material-removal rate for SCD fell from 0.62 to 0.18 μm/min over sixty minutes, whereas AD remained high, starting at 5.2 and ending between 3.9 and 4.1 μm/min. The fused quartz wafer surface roughness Ra after lapping reached 15.6 nm with SCD and 52.6 nm with AD. Results revealed distinct shifts in material removal modes as diamond particles underwent wear and blunting. The root mean square of AE signal rose and fell in step with MRR for both SCD and AD, confirming a strong positive correlation between signal magnitude and material removal. Characteristic AE frequencies were identified for micro-cutting, plowing, debris movement, and AD micro-fracturing, enabling non-contact monitoring of these processes. Analysis revealed a distinct peak near 0.22 MHz, attributable to micro-cutting, and another around 0.28 MHz, corresponding to plowing. Additionally, frequencies in the 0.60–0.75 MHz range observed in the AD pad indicate micro-fracturing associated with self-sharpening behavior. This non-destructive technique offers significant potential for optimizing FA lapping parameters to achieve desired material removal rates and surface finishes. </p> <!-- END_ABSTRACT --> <!-- START_TEMPLATE --> <ul> <li> Source: </li> <li> Tags: </li> </ul> <!-- END_TEMPLATE -->