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通过复合添加Mn,B并结合机械振动研究了再生铝合金A356的显微组织形态、分布及力学性能,探讨了复合添加Mn,B和机械振动对合金凝固过程的作用和组织细化的机制。结果表明:单独添加Mn元素能显著改善再生铝合金A356中的富铁相形貌,富铁相形貌基本呈汉字状;施加机械振动后,合金中含Mn元素的四元富铁相开始聚集形成多边形块状富铁相,且晶内弥散分布的富铁相数目减少。复合添加Mn,B元素可有效降低再生铝合金A356中杂质铁含量,当添加Mn=1.2Fe(质量比)和3%Al-3B(质量分数)合金时,合金中杂质铁含量从0.96%降低至0.43%,除铁率为55.2%,其合金中的晶粒大小较单独添加Mn元素处理的更为细小,且合金组织中的富铁相的数量较单独添加Mn元素的少。对其施加频率为30Hz的振动后,合金力学性能达到最优,其室温抗拉强度和伸长率分别为177MPa,10.92%。
The microstructure, distribution and mechanical properties of the recycled aluminum alloy A356 were studied by adding Mn and B in combination with mechanical vibration. The effects of the addition of Mn, B and mechanical vibration on the solidification process and microstructure of the alloy were also discussed. The results show that the addition of Mn can significantly improve the morphology of iron-rich phase in the regenerated aluminum alloy A356. The morphology of the iron-rich phase is basically in the form of Chinese characters. After the mechanical vibration is applied, the quaternary iron-rich phase in the alloy begins to accumulate A polygonal massive iron-rich phase is formed, and the number of iron-rich phases dispersed in the crystal decreases. The addition of Mn and B elements can effectively reduce the content of iron in the recycled aluminum alloy A356. When adding Mn = 1.2Fe (mass ratio) and 3% Al-3B (mass fraction), the content of iron in the alloy decreases from 0.96% To 0.43% and the iron removal rate is 55.2%. The grain size of the alloy in the alloy is smaller than that of Mn alone, and the amount of iron-rich phase in the alloy is less than that of Mn alone. After the vibration frequency of 30Hz was applied, the mechanical properties of the alloy reached its optimum. The tensile strength and elongation at room temperature were 177MPa and 10.92% respectively.