Semi-solid extrusion forming of spray deposited Al-27%Si alloy

The semi-solid extrusion and its effect on the microstructure and properties of spray deposited Al-27%Si alloy were studied. The result shows that, the alloy have appropriate liquid volume fraction and fine Si particles for semi-solid extrusion after reheating at 600°C for 10-12 min. The extrusion after reheating at 600°C for 10-12 min can eliminate the hole in the spray deposited alloy and decrease the size of Si particles, extruded bars have good surface quality and homogeneous microstructure after extrusion. The alloy can achieve the highest relative density (99.5%), tensile strength (195 MPa) and elongation (6.7%) after semi-solid extrusion when reheating at 600°C for 12 min.