Investigation Into the Effect of Cryogenic Minimum Quantity Lubrication in High-Speed Milling of Titanium Alloys

High-speed milling of titanium alloys generates high cutting temperature at cutting zone and leads to rapid tool wear. This paper is focused on effect of cryogenic minimum quantity lubrication (CMQL) on cutting force and tool wear in high-speed milling of titanium alloys by uncoated carbide inserts. Dry milling and refrigerated air cooling experiments were also conducted for comparison. Results indicated that as compared with dry milling and refrigerated air cooling conditions, there is a considerable reduction in cutting force and tool wear for CMQL due to its superior lubrication effect. The scanning electron microscope (SEM) investigation of the worn cutting tool inserts shows that adhesion wear, diffusion wear and thermal fatigue wear are the main wear mechanisms of uncoated carbide inserts when high-speed milling titanium alloys under CMQL condition. Application of CMQL does not result in severe thermal fatigue wear even when milling titanium alloys at a higher cutting speed.