Incorporating Electromagnetic Stirring into Semisolid Casting of AXE622 Mg Alloy: Effect of Process Parameters on Microstructure and Mechanical Properties

The present study investigates the effect of electromagnetic stirring parameters on the microstructure and mechanical properties of the AXE622 semisolid cast alloy. According to the results, the shape factor does not differ significantly at 150 s, 270 s, and 390 s of stirring time, whereas the average grain size reaches its lowest value of 47 μm, at 270 s of stirring time. The maximum microhardness (57.3 HV), tensile strength (148 MPa), and uniform elongation (3.1%) were achieved after stirring for 270 s. As the pouring temperature decreased from 600 °C to 595 °C, and then to 585 °C, the average grain size decreased continuously from 55 to 32 μm. In this regard, the highest shape factor (0.7) was obtained at a pouring temperature of 595 °C. The semisolid cast alloy poured at 595 °C exhibited 148 MPa tensile strength and 3.1% uniform elongation, which demonstrates improvement compared with the semisolid cast alloy poured at 585 °C (108 MPa, 1.9%) and 600 °C (119 MPa, 2.3%). As the stirring frequency increased from 15 to 47 Hz, the average grain size increased from 45 to 54 μm, and the shape factor decreased from 0.73 to 0.65. Tensile strength improved from 136 to 148 MPa as stirring frequency increased from 15 to 32 Hz, and microhardness value increased from 54.2 to 57.3 HV. No matter what the semisolid parameters are, the semisolid process provides better mechanical and microstructural properties than conventional cast alloy.