Influence of tool hardness on tool wear, surface roughness and acoustic emissions during turning of AISI 1050

In this work, chemical vapor deposition (CVD) coated carbide inserts with different hardness of P types entitled as hard, semi-hard and tough are utilized for turning of AISI 1050 steel. Flank wear, surface roughness, cutting force, acoustic emissions and chips morphology were considered under dry turning conditions for the comparison of the effect of cutting speed, feed rate and cutting tool hardness. The novelty of the study is to investigate comprehensively the effect of tool hardness along with cutting parameters on the the machinability characteristics. This approach provides to understand the underlying mechanism of tool wear and its influence on the surface properties of the workpiece which is useful in practice for upgraded machinability. The results indicated that the tool hardness affects flank wear dramatically followed by surface roughness and acoustic emissions values and ideal values of cutting conditions are attained with semi-hard tool. Scanning electron microscope (SEM), energy dispersive spectrum (EDX) and mapping analysis also demonstrated the wear developments are distinctive with using different types of tool hardness values. The findings depicted that tool hardness has significant impact on machining characteristics which need to be dealed under particular cutting conditions. 65 HRC of cutting tool provides better machinability in terms of surface roughness, tool wear, acoustic emissions and cutting forces followed by 60 HRC and 70 HRC respectively.