Influence of Al content on machinability of AM series magnesium alloys

Abstract

This study investigates the effects of Al (aluminium) amount in AM series magnesium alloys on mechanical properties and machinability (cutting forces). Changes in microstructure and mechanical properties and their effects on cutting forces were analysed depending on the increase in Al amount. For this reason, AM series magnesium alloys (AM20, AM40, AM60, and AM90) with varying amounts of Al % (from 2 to 9 %) were used in the study. It was observed that in AM series magnesium alloys (containing 0.5 % Mn), intermetallic phases found in microstructure (Mg17Al12 and Al8Mn5) improved the mechanical properties and lowered machinability by rising the cutting forces (Fc) depending on the increase in Al amount. Also, the surface roughness (Ra) of intermetallic phases was observed to have an impact on flank build-up – FBU and chip formation. While AM90 had the highest values in terms of mechanical properties and surface quality, AM20 had the lowest values. On the other hand, AM20 had the highest El% values and machinability properties.