Effect of Ni addition on tensile properties of squeeze cast Al alloy A380

Abstract

The influence of transition alloying element nickel to the tensile properties of squeeze cast aluminum alloy A380 as one of the most common used hypoeutectic Al–Si–Cu alloys was investigated. Nickel (Ni) addition varying from 0.5 up to 2.0 wt.% was introduced into A380. The alloyed melt was squeeze cast under an applied pressure of 90 MPa. The results of tensile testing on the Ni-containing A380 alloys show that Ni is an effective additive for improving their tensile properties, in particularly, tensile and yield strengths and resilience at room temperature. As the Ni addition increases from 0 to 2.0 wt.%, the ultimate tensile and yield strengths and resilience rise to 225.40 MPa, 128.04 MPa and 175.90 kJ/m3 respectively. The as-cast microstructures of the squeeze cast conventional and Ni-containing alloys were observed by an optical microscope(OM). Examination of the analyzed microstructures indicates that the complex Ni-containing intermetallic phases forms once Ni addition. The presence of the Ni-containing intermetallic phases should be responsible to the improvement of mechanical properties. Based on the density measurements, it is found that the introduction of 2.0 wt.% Ni into the A380 results in a trivial effect on its density by only 0.5%.