Some studies on high-pressure cooling in turning of Ti–6Al–4V

Abstract

Titanium alloys are being increasingly employed in engineering and bio-medical applications, but their manufacturability via the cutting and grinding process is always a problem, which needs to be overcome. Inherent characteristics of Ti–6Al–4V alloy promote rapid tool wear, which needs to be curbed in order to attain high efficiency in metal cutting. Conventional or low-pressure cooling method fail to effectively conduct away the heat generated in the cutting zone, which is responsible for short tool life. High-pressure coolant jets were directed into the tool–chip interface to sufficiently penetrate and change the thermal, frictional and mechanical conditions in the cutting zone. High-pressure cooling using neat oil and water-soluble oil was undertaken and its effects on machining evaluation parameters such as chip form, chip breakability, cutting forces, coefficient of friction, contact length, tool life and surface finish of the finished workpiece were evaluated in comparison with those from the conventional cooling method. The results show that significant improvement in tool life and other evaluation parameters could be achieved utilising moderate range of coolant pressure.