9th International Advanced Technologies Symposium, Elazığ, Turkey, 27 - 28 October 2021, pp.379-384
In this study, the effects of strontium (Sr) additions at different rates (0.02, 0.1 and 1 wt%) to the Al-12Si alloy on structural, mechanical and machinability properties were investigated. Each alloy was manufactured by the permanent mold casting method. The microstructures of the manufactured alloys were examined using an optical microscope. While hardness of alloys was determined by Brinell method, strength values were determined by tensile tests. Machinability tests were performed on a CNC lathe at constant cutting speed (200 m/min), feed rate (0.15 mm/rev), depth of cut (1.5 mm) using CVD-TiCN/TiN coated carbide insert. Microstructure investigations showed that Al-12Si-0.02Sr alloy was composed of
aluminum-rich α, thin and spherical shaped eutectic Al–Si, primary silicon and fiber shaped Al–Fe–Si phases. Al-Si-Sr phase was observed in Al-12Si-0.1Sr and Al-12Si-1Sr alloys apart from the existing phases. The hardness and tensile strength values of the manufactured alloys increased up to 0.1% Sr and decreased after this rate. In the machinability tests, it was determined that the cutting force and surface roughness decreased as the Sr ratio increased from 0.02% to 0.1%. However, it was observed that the highest cutting force and surface roughness values were measured with the addition of 1%Sr. The experimental results were based on the structural properties of the alloys.