Effect of Refrigerated Air Cutting on Tool wear in High-speed Cutting of Difficult-to-cut Materials

A refrigerated air/cryogenic minimum quantity lubrication generator was developed based on a composite refrigeration method. TiAlN coated carbide tool was used in high-speed turning of Inconel718 nickel-base superalloy and high-speed milling of AISI D2 hardened steel. Experiments were conducted under different cooling/lubrication conditions, i.e. dry cutting, minimum quantity lubrication (MQL), refrigerated air, and cryogenic minimum quantity lubrication (cryogenic MQL). SEM and EDS were used to analyze wear morphologies and mechanism of cemented carbide tools. Thus effect of refrigerated air and cryogenic MQL on tool wear was investigated in high-speed cutting of difficult-to-cut materials. The results showed that the main tool wear mechanism was abrasive wear, adhesive wear and diffusion wear in high-speed cutting of difficult-to-cut materials. Application of refirgerated air and cryogenic MQL in the high-speed cutting of difficult-to-cut materials reduced the cutting temperature effectively, which avoided the intenerate of cutting tools, and reduces abrasive wear and thermally related wear such as adhesive wear and diffusion wear. Therefore, refrigerated air and cryogenic MQL enhanced tool life remarkably.