A comparative study monitoring the wear of CVD diamond coated carbide inserts and polycrystalline diamond inserts while turning metal matrix composites

摘要

A cutting performance study was conducted on CVD Diamond Coated inserts obtained from various manufacturers. Polycrystalline Diamond (PCD) inserts were used to generate baseline cutting data for this comparative study. The turning tests wereperformed on Duralcan Metal Matrix Composite (MMC) A359/SiC/20p-T6 bars at two cutting speeds and feeds. The study showed that while PCD inserts are still a good choice in MMC machining, depending on the thickness of the diamond film and its adhesion tothe substrate, CVD inserts outperformed the PCD inserts. The wear characteristics of both types of tools which were examined using optical microscopy and scanning electron microscopy were found to be different. The wear on the PCD inserts resulted in arapid pullout of the diamond particles, while on the CVD diamond coated inserts it contributed to the polishing of the wear zone. The surface finish of the workpiece material was also monitored during the study.