Experimental investigation on the performance of helical milling for hole processing in AZ31 magnesium alloy

A comparative evaluation of conventional drilling and helical milling to process holes in AZ31 Magnesium alloy is reported. The results highlight the advantages of helical hole milling over the mechanical drilling process in terms of lower machining forces. Besides, the process is successful in reducing the machining temperature and size of the burrs formed, in addition to improved surface finish. Further, analysis of the helical hole milling process demonstrated that the axial pitch has a dominating influence on the thrust force, whereas the feed value greatly influences the radial force. The spindle speed is found to influence the machining temperature significantly. The chip morphology is found to be dependent on feed and axial pitch, with the feed value influencing the chip segmentation and breakability. The absence of burn marks on the chip surface indicates a lower risk of fire hazard.