Cutting forces and tool wear in intermittent turning processes with Al 2O3-based ceramic tools

Orthogonal and single factor intermittent turning experiments of hardened AISI 1045 steel were conducted with two kinds of Al2O3-(W, Ti)C ceramic tools used, aiming to reveal the effects of cutting parameters on cutting forces, the influence of mechanical and thermal loads on tool wear mechanisms at different wear evolution stages. Empirical formulas for average cutting forces and tool lives (impact number of tools under two different flank wear limits 0.1 mm and 0.3 mm) were established respectively. The worn or fractured surfaces of the tools tested at different cutting speeds were analyzed using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). It is found that feed rate and depth of cut had greater influence on the average cutting forces in cutting periods than cutting speed did. The amplitude of the vibration generated in the radial direction decreased with increasing cutting speed, while that of the vibration generated in the other two directions increased. The influences of mechanical and thermal loads on tool wear changed in different ways at different stages of tool wear evolution process. There existed critical cutting speeds above which adhesive wear of the ceramic cutting tools became less serious. © (2012) Trans Tech Publications, Switzerland.