Impacts of flank wear and cooling strategies on evolutions of built-up edges, diffusion wear and cutting forces in Ti6Al4V machining

Titanium alloys are widely used in aerospace industries due to their excellent physical and mechanical performances, however, their poor machinability always induce fast tool wear. To better understand the interaction between progressive tool wear and cooling strategies in machining of titanium alloy Ti6Al4V, an in-depth analysis towards evolutions of built-up edges (BUEs), diffusion wear and cutting forces was carried out through experimental work. Design of experiments was used towards analyzing pertinent effects involved in machining Ti6Al4V. Uncoated carbide inserts were artificially treated with different initial flank wear (VB) in order to decouple the effects involved in progressive wear condition from rake and flank faces. Dry cutting, flood cutting with emulsion and cryogenic cutting with liquid nitrogen (LN2) were used as different cooling strategies. The results show that initial VB presents significant contributions to BUEs formation, diffusion wear and cutting forces fluctuation, especially under aggressive cutting conditions. Cryogenic assistance significantly eliminates these issues compared to dry and flood conditions.