Abstract
The alloys of the beta allotropic form of titanium are among the most difficult-to-cut materials. An extremely poor machinability calls for special ways of performing machining with an emphasis on developing new methods of heat dissipation. The paper focuses on evaluating effectiveness of using CO2 snow as a coolant in continuous machining of a beta-titanium alloy. It also explores the most appropriate location of its application in the cutting area and usefulness of its hybridization with minimum quantity of lubrication. The effectiveness of using the two cutting fluids is compared with an emulsion-based flood coolant. The effects of varying work material's yield strength and cutting speed are also investigated. The measured responses include tool displacement area (a measure of tool deflection obtained from tool acceleration data), cutting energy consumed (obtained from acoustic emissions data), and tool wear. The results show that the usage of CO2 snow and its location of application possess a significant effect on the responses. The combination of CO2 snow and minimum quantity of lubrication is found to be the most effective way of heat dissipation and lubrication. With regard to tool damage, the scanning electron microscopy shows the presence of gradual wear and cutting speed-dependent adhesion but no evidence of chipping. The paper also presents a possibility of estimating tool damage condition through acoustic emission and tool deflection data. In this regard, a strong uphill relationship between tool wear and cutting energy is observed.