轻质铝合金的变质研究

Study on Modification of Light Aluminum Alloy

一定含量的铁元素添加到轻质铝合金中,合金的抗拉强度提高,塑性下降。在铝合金中加入微量钪锆元素进行变质处理,合金组织中的长针状Al;Fe相更加细小,并有生长成自由树枝状相的趋势;Al基体轮廓更加清晰,组织均匀细化。组织改善提高了合金的综合力学性能。合金的抗拉强度达到了152.5 MPa,相比变质前提高了55%,伸长率也略有提高。最后分析了凝固过程中钪锆变质对各相结晶条件的影响和细化机理。

When a certain amount of iron is added to the light aluminum alloy, the tensile strength of the alloy increases and the plasticity decreases. The modification treatment was carried out by adding a small amount of the scandium and zirconium to the aluminum alloy. The long needle Al;Fe phase in the alloy microstructure is smaller and has a tendency to grow into free dendritic phases. The outline of Al matrix in the alloy is more clear and the microstructure is evenly refined.The improved microstructure improves the comprehensive mechanical properties of the alloy. The tensile strength of the alloy reaches 152.5 MPa, which increases by 55% compared with that of the alloy before modification. And the elongation rate is also slightly increased. At last, the effects and refinement mechanism of scandium and zirconium metamorphism on the crystallization conditions of each phase during solidification were analyzed.