Hole-making and its Impact on the Fatigue Response of Ti-6AL-4V Alloy

Abstract

In this work, the impact of conventional drilling and helical milling processes on the fatigue response Ti-6Al-4 V (grade 5 titanium alloy) has been presented. Results show that the work pieces produced by helical milling has a 119% longer fatigue life compared with the drilled pieces under dry machining condition, and a 96% longer fatigue life for helical milled piece under lubricated condition. The use of cutting fluid has led to longer fatigue lives – 15% longer for drilling and 3% longer for helical milling. Other results such as the machined surface roughness, alloy surface and sub-surface microstructures have also been studied in details.