Monitoring and prediction of tool wear in microturning of copper

This paper presents experimental results of microturning of commercially available copper rods with cermet (TiC + Al2O3) inserts as cutting tool. Machining was done in DT-110 integrated multiprocess micromachine tool. Full factorial experiments were conducted with various combinations of cutting speed, feed and depth of cut. Tool wears for different conditions were measured offline and also acoustic emission signals (AE rms) were recorded. Variations of tool wear with time and correlation between AE rms and tool wear were studied. Good correlation was observed between AE rms and tool wear. SEM images of worn tool shows fairly uniform structure around the cutting edge without any material erosion. Also crater wear was observed on the rake face with formation of a ledge. It was found that mostly steady machining can be obtained with medium speed and feed.