A Comparative Study of Energy and Material Flow in Modulation-Assisted Machining and Conventional Machining

A study has been made of deformation, forces and energy in modulation-assisted machining (MAM), wherein chip formation occurs in the presence of a controlled, low-frequency modulation superimposed on to the machining. A unique feature of the study is the use of high speed in situ imaging and image analysis to map material flow in the chip formation zone at high resolution; and simultaneous measurements of tool motions and forces, such that the instantaneous forces can be overlaid onto the chip formation process. The measurements show that the observed significant reductions in specific energy in MAM relative to conventional machining, when cutting ductile metals such as copper and Al 6061T6, are a consequence of chip formation with reduced strain levels in MAM. Additional insights into the chip formation are obtained by examining the effects of a chip aspect ratio parameter.