Wear mechanisms of coated mixed-ceramic tools during finish hard turning of hot tool die steel

The present study aims to investigate the wear mechanisms of a TiN-coated mixed ceramic tool prevalent under different machining conditions during hard turning Of hot tool die steel. The different wear mechanisms observed are abrasion wear at low Cutting speed, low feed rate, and highest work piece hardness; formation of protective layer and built-up edge (BUE) resulting from tribochemical reactions between constituents of tool and work piece material at moderate speed. High temperature accompanied by high cutting speed resulted in the removal of the protective layer and Suppressed the BUE formation. Hard carbide particles of work material at a higher feed rate severely gouged the tool flank land. Chipping and brittle fractures were observed at very low and high depth Of Cut. Adhesion of work piece material Followed by plastic deformation and notching was clearly visible at low work piece hardness. The influence of cutting speed, feed rate, depth of cut, and work piece hardness on the progressive tool flank wear, and flank wear rate (VBr-mu m/km) in the steady wear region was also analysed.