Analysis of tool-chip interface characteristics of self-lubricating tools with nanotextures and WS 2 /Zr coatings in dry cutting

The environmental obligations of manufacturing industries have resulted in the development of new cutting tools during metal machining without cutting fluids. According to the green manufacturing principles and to further improve the cutting performance of tools in dry cutting, novel cutting tools combined with nanotextures and WS2/Zr coatings (AN-AW) are developed, and cutting tests without cutting fluids on hardened steel exhibit that the AN-AW tool is the most effective in reducing the cutting forces compared with the WS2/Zr-coated tool (AS-W) and conventional tool (AS). Based on the experiments and theoretical models, the tool-chip interface characteristics are further investigated quantitatively to analyze the mechanism of the AN-AW tool. Results show that the AN-AW tool has a significant effect on the tool-chip interface characteristics. The AN-AW tool is the most effective in reducing the friction coefficient and tool-chip contact length; meanwhile, it changes the stress distribution at the tool-chip interface. The reduced tool-chip contact length and sticking-total contact length ratio as well as the lubricant film formed by the WS2/Zr coatings at the tool-chip interface may be responsible for the changes of friction and stress distribution for the AN-AW tool.