Effect of Si content on machinability of Al-Si alloys

This study investigates the effect of the change in the amount of Si found in Al-Si alloys on mechanical properties and machinability properties of the alloy. The way the microstructure and the mechanical properties change depending on the increase in the %Si amount in the alloy and the effects of such changes on Flank Build-up (FBU), wear in the cutting edge, surface roughness, and machinability were analysed. To this end, alloys with varying amounts of silicon (i.e., 2 to 12 wt.% Si) were used in the study. Experimental samples were obtained by casting in sand moulds. It was observed in the study that, in Al-Si alloys, the mechanical properties and machinability of alloys increased depending on the rise in %Si in the alloy, that cutting forces decreased, and accordingly, machinability increased. It was also observed in the study that the increase in the %Si amount raised the surface quality (decrease in surface roughness).