Abstract:Influence of Al content on the machinability of AZ series cast Mg alloys was investigated. In order to evaluate the machinability of the alloys, measurements of the cutting forces during turning operations and surface roughness were carried out as well as considering the microstructure and tensile properties. The results show that maximum tensile properties are observed with 2% (mass fraction) Al addition to Mg. As the Al content of the alloy increases above 2%, the cutting forces tend to reduce along with the ductility owing to the grain boundary precipitation of intermetallic phase (β-Mg₁₇Al₁₂). Cutting forces are able to increase as the cutting speed increases for all the alloys studied, and it’s attributed to flank built up at the tip of the cutting tool during machining.

Key words: machinability; cutting force; Mg; AZ series alloys