On-machine tool resharpening process for dry machining of aluminum alloys employing LME phenomenon

• In dry machining of aluminum alloys, aluminum adhesion on tool surface significantly deteriorates cutting performance.
• Mechanical properties of aluminum adhesion layer on tool surface were investigated.
• Novel on-machine tool resharpening process employing LME phenomenon was newly developed.
• The developed process successfully removed aluminum adhesion from tool surface.
• The resharpened tool shows excellent cutting performance nearly equivalent to its virgin state.

Dry machining of aluminum alloys is known to be one of the most difficult metal cutting operations. The issues involved are that without use of cutting fluids, these materials severely adhere to the tool surface and form a built-up edge due to their low melting point and high ductility, leading to deterioration of the surface integrity of the workpiece and tool failure. To overcome this problem, the present study proposes a novel strategy for removing the adhesion layer from the tool surface and recovering the cutting tool performance without detaching the cutting tool from the machine tool, namely, an on-machine tool resharpening process. To achieve efficient removal of the aluminum adhesion layer from the tool surface, the phenomenon of liquid metal embrittlement (LME), which is defined as a brittle fracture, or loss in ductility, of a ductile material in the presence of a liquid metal is employed. A series of experiments using a WC-Co cemented carbide tool and liquid gallium showed that the newly developed strategy employing LME is highly effective in removing the adhesion layer without damage to the tool substrate and has great potential for addressing the issues related to the dry machining of aluminum alloys.