Development and Application of Heat-Treatment Free Aluminum Alloy for Integrated Die-Casting
To obtain high-performance heat-treated free aluminum alloys,3 kinds of Al-Si based heat-treated free aluminum alloys with different composition ratios are designed by adjusting the mass fractions of each element in the alloy.The melting temperature range,structure phase composition,fracture morphology,tensile and fatigue performance of 3 kind of alloys are analyzed by using Differential Scanning Calorimeter(DSC),metallographic microscope,scanning electron microscope,tensile testing machine and electromagnetic resonance fatigue testing machine.The results show that 2#alloy has good casting fluidity,metallographic structure,comprehensive strength and toughness properties and casting manufacturability,with a melting temperature range of 55℃,the tensile strength,yield strength and elongation rate at break are 303 MPa,153 MPa and 11.3%,respectively.The average axial tensile compressive fatigue strength at 1×107 cycles is 125 MPa,which is superior to the fatigue performance of AlSi9Cu3(Fe)die-casting alloy commonly applied in the automotive industry.