Advisor(s)
Abstract(s)
Machining of titanium alloys such as Ti-6Al-4 V can be very intimidating due to their low thermal conductivity
leading to elevated cutting temperatures at the chip-tool interface (ICT). In this regard, the self-lubrication effect
of coatings like TiSiVN represented by topography, oxidation, and diffusion at the chip-tool interface are crucial.
Thus, the present work investigates the latter three mechanisms during dry machining of Ti-6Al-4 V titanium
alloy with uncoated and TiSiVN coated Al2O3/SiC whiskers-reinforced ceramic cutting tools. The results reveal
that the adhesion height (AH) and O% increases with cutting temperature, showing the dominant influence of
cutting temperature on material adhesion and oxidation levels at the ICT. AH increases with increased cutting
speed for both coated tools, indicating that the crater depth increment was not so severe for the coated tools.
However, a drastic upward surge of crater depth for uncoated and TiSiN coated tools at 125 m/min cutting speed
makes the crater edge near the ICT act as a chip breaker and facilitates the chip’s bending away from the tool face
causing reduction in chip bend angles (BA). Additionally, the TiSiVN coating accounts to a reduction of
approximately 23% in AH and 18% in Ti%, and 37% lower oxygen levels at the highest cutting speed when
compared to the uncoated tool primarily due to lower cutting temperatures and self-lubricating behavior.
Description
Keywords
TiSiVN self-lubricating coating surface roughness Ti-6Al-4V machining
Citation
Publisher
Elsevier Ltd.