Refinement and modification performance of Al–P master alloy on primary Mg2Si in Al–Mg–Si alloys

Refinement and modification performance of Al–3P master alloy on primary Mg2Si in Al–12.67Mg–10.33Si alloys were investigated in this paper. The experimental results show that the perfect effect can be obtained after the addition of 3% Al–3P master alloy into the Al–Mg–Si alloys. The morphologies of primary Mg2Si particulates change from dendritic to polygonal shape, and their average sizes decrease from ∼100 to ∼20 μm. Further, the ultimate tensile strength increases from 252 to 275 MPa. Also, the melt treating technological parameters were established in this paper, treating temperature is 850 °C, holding time is 30 min. EPMA results show that AlP particles act as the nuclei of primary Mg2Si.