Research on cutting performance of hard carbon coated tools in dry drilling Al-Si alloy

The hard carbon solid lubrication coating was deposited onto high-speed steel (HSS) twist drills by closed filed unbalanced magnetron sputter ion plating technique. The drilling tests were performed on Al-Si alloys under dry cutting conditions. By the analysis and comparison of the flank wear, the drilling forces and the drilling precision on coated and uncoated drills, the cutting performance of the hard carbon solid lubrication coated HSS tools was researched. The results show that the hard carbon coating with high hardness and low friction coefficient can significantly improve the cutting performance of HSS twist drills, prolong the tool life, decrease the drilling forces and improve the drilling precision. Due to its good adhesion and match with HSS substrate, and proper thickness, the graphite-like carbon (GLC) solid lubrication coatings has great potential for dry cutting operations, and it would be one of the most perspective tools coating in dry cutting Al-Si alloy.