Comparative multiscale investigations of material removal behaviors of SiCp/5083Al, SiC ceramic and 5083Al alloy by single scratch tests

To gain a deep insight into the material removal mechanism of high volume fraction SiCp/Al during a grinding process, comparative multiscale investigations of material removal behaviors of 50 vol% SiCp/5083Al, bulk SiC and bulk 5083Al are presented by single scratch tests. Scratch mechanical properties including scratch force, friction coefficient and AE signal, as well as cross-sectional profile including residual scratch depth and material removal ratio are introduced to measure material removal behaviors at macroscale and mesoscope. Moreover, surface morphology of scratch grooves with help of SEM micrographs and explanatory model of material removal mechanisms are used to understand material removal evolution at microscale. It has demonstrated that at macroscale and mesoscope material removal behaviors of SiCp/5083Al are similar to that for 5083Al, but different from that for SiC, at microscale essentially different from that for 5083Al and SiC. Normal force (scratch depth) has significant influence on material removal behaviors, a sufficiently low scratch depth could achieve ductile removal of particles SiC resulting in a comparatively good surface for SiCp/5083Al, otherwise, the reverse. The work findings provide a critical insight of the material removal mechanism for SiCp/Al by considering coupling effects of particles SiC and matrix Al, and critical information for improving grinding quality. (paper)