Effect of Mn/Fe Ratio on the Microstructure and Properties of Al-Mg-Si Alloy
Taking Al-Mg-Si alloy as the research object,the casting made by permanent mold casting was used to study the effect of Mn/Fe ratio on its structure and properties.The results indicated that there were α-Al matrix and a large number of precipitated phases between the dendrites in the or structure of Al-Mg-Si cast alloys,which were mainly dominated by Mg2Si phases,and there were also a small amount of eutectic Si phase,AlFeSi phase and Al(FeMn)Si phase.With Mn/Fe ratio increased,the grains in the alloy gradually become fine and rounded,and transform from dendrites to equiaxed grains.Mn could promote the transformation of the needle-like β-AlFeSi phase to the skeletal,granular or massive α-Al(FeMn)Si phase in aluminum alloys.The thermal conductivity of the alloy reached a maximum value of 181.08 W·m-1·K-1 at a Mn/Fe ratio of 0.5.The alloy had the smallest grain size and the best mechanical properties at a Mn/Fe ratio of 1.0.When compared to Mn/Fe of 0.2,the tensile strength,elongation,and hardness increased by 17.45%,49.57%,and 31.82%,respectively,reaching 167.35 MPa,17.23%,and HV 86.26.
万方数据
维普
