Wear behaviors of PCD and diamond-coated tools during low-frequency vibration-assisted drilling CFRP/Ti stacks

Abstract

Carbon ber reinforced polymer (CFRP) and titanium alloy stacks play a signi cant role in the aerospace eld to improve the mechanical properties of assembly components. Low-frequency vibration-assisted drilling (LFVAD) can realize the periodic contact and separation characteristic between the tool and the workpiece, thus pose a high potential for manipulating the machinability of CFRP/Ti stacks. In the present study, two types of drilling tools (polycrystalline diamond (PCD) tool and diamond-coated tool) are adopted and tool wear behaviors are deeply evaluated during drilling CFRP/Ti stacks. Meanwhile, the speci c in uences of tool wear on the drilling performances are comprehensively analyzed under the LFVAD with minimum quantity lubrication (MQL). The results show that Ti-adhesion is observed for both drilling tools. Meanwhile, edge fracture is the key wear mode dominating for PCD tool and coating peeling is the main wear mode for diamond-coated tool, with less Ti-adhesion. In addition, with increasing number of drilled holes, the diamond-coated tool demonstrates better drilling performances with lower cutting force, better hole quality and more hole-making number. The ndings of this paper can contribute to providing a guidance for tool optimal selection in low-frequency vibration-assisted drilling of CFRP/Ti stacks with MQL.(4) With lower thrust force and temperature, the diamond-coated tool favors the suppression of the exit burr and delamination. However, near the end of tool life, the both elements increase almost exponentially, indicating that the protective effects of the diamond coating decayed rapidly. DeclarationsAuthors' contributions Dexiong Chen, Yan Chen and Chaoren Yan contributed to the conception of the study.