Microstructure Evolution and Mechanical Properties of Spray-deposited Al-21.47Si-4.73Fe-2.5Cu-0.9Mg Alloy

Al-Si-Fe-Cu-Mg alloy was prepared by spray deposition and was further processed by hot extrusion as well as T6 heat-treatment. The results indicate that the microstructure of the deposited alloy is composed of primary Si particles with average size of less than 5 mu m, alpha-Al, Al2CuMg, beta-Al5FeSi and delta-Al4FeSi2(rectangular shape), and no eutectic silicon is found due to the special solidification behavior. The age hardening curves reveal two peaks. The uniform ultimate tensile strength CUTS) and the elongation of the peak-aged Al-Si-Fe-Cu-Mg alloy are 468. 3 MPa, 0. 61% at 298 K and 267. 4 MPa, 6. 42% at 573 K, respectively. The fracture surfaces display brittle fracture morphology at 298 K, whereas it varies to mixture of brittle and ductile failure with increasing the temperature.