Experimental study on machinability improvement of hardened tool steel using two dimensional vibration-assisted micro-end-milling

High strength, low thermal conductivity and high work hardening tendency of tool steel are the main factors that make its machinability difficult. In this paper, two dimensional vibration-assisted micro-end-milling (2-D VAMEM) is applied to machine the hardened tool steel (HRC 55 and HRC 58) in order to improve its machinability. The experiments are carried out to study the effects of vibration parameters on the surface roughness and the tool wear. It is found that 2-D VAMEM can improve the surface roughness and reduce the tool wear compared to traditional micro-end-milling, and larger amplitude and higher frequency are useful for the surface roughness improvement and the tool wear reduction. Therefore, 2-D VAMEM is an effective method to milling of hardened tool steel and can be applied in the manufacture of moulds and dies with improved machining efficiency, surface quality and tool life.