犆犪犃犾质量比对犕犵犃犾犆犪犕狀合金组织和性能的影响

The effects of Ca, AI mass ratio on the microstructure and mechanical properties of as-cast Mg-Al-Ca-Mn alloys were investigated. The results indicate that when the Ca, Al mass ratio is 0.4, the secondary phase in the as-cast Mg-5Al-2Ca-0.4Mn alloy is composed of (Mg,Al)₂Ca phase. When the Ca,AI mass ratio is 0.75, the secondary phases in the as-cast Mg-4Al-3Ca-0.4Mn alloy are composed of (Mg, Al₂)Ca phase and Mg, Ca phase. When the Ca,Al mass ratio is 1.3, the secondary phase in the as-cast Mg-3Al-4Ca-0.4Mn alloy is composed of Mg₂Ca phase. With the increase of Ca, Al mass ratio, the secondary phase in the alloy is converted from (Mg, Al₂)Ca phase into Mg₂Ca phase, where the layer spacing is gradually decreased and the volume fraction is gradually increased. Moreover, the yield strength of the as-cast Mg-Al-Ca-Mn alloy is increased from 82 MPa to 123 MPa with Ca,Al mass ratio increasing, while the elongation is decreased from 5.0% to 1.1%.