铸造温度对AlSi9Cu3(Fe)合金显微组织的影响

    Effect of Casting Temperature on Microstructure of AlSi9Cu3(Fe) Alloy

    • 摘要: AlSi9Cu3(Fe)铝合金是铸造铝合金中使用较为广泛的合金,铸造温度是亚共晶铝硅合金获得优良力学性能的重要加工参数。通过研究不同铸造温度下AlSi9Cu3(Fe)合金中α-Fe和β-Fe的含量,推导含铁化合物相的演化过程。在680~960℃之间,以70℃为间隔,选择5种不同温度制备得到Fe含量约为0.7wt%的AlSi9Cu3(Fe)合金。结果表明,在不同铸造温度下,AlSi9Cu3(Fe)合金的二次枝晶臂间距没有显著变化。当铸造温度高于890℃后,有害相β-Fe的析出受到了一定程度的抑制。同时,块状或汉字状的α-Fe相成为微观结构的主导相。当铸造温度较高时,富Fe相结晶成稳态β-Fe相的平衡条件被打破,更容易形成亚稳态的α-Fe相。

       

      Abstract: AlSi9Cu3(Fe) aluminum alloy is widely used in casting aluminum alloy.Casting temperature is an important process parameter to obtain excellent mechanical properties of hypoeutectic Al-Si alloy.The evolution of Fe-containing intermediate compounds in AlSi9Cu3 (Fe) cast aluminum alloy by testing the α-Fe and β-Fe content at different casting temperatures was studied.AlSi9Cu3 (Fe) alloys with Fe content of about 0.7wt% were prepared at different temperatures ranging from 680 ℃ to 960 ℃ and casting temperature interval of 70 ℃.The results show that the secondary dendrite arm spacing of AlSi9Cu3(Fe) alloy does not change significantly at different casting temperatures.When the casting temperature is higher than 890℃, the precipitation of harmful β-Fe phase is inhibited in a certain extent.At the same time, the bulk or Chinese character shape α-Fe phase becomes the dominant phase of the microstructure.When the casting temperature is high, the equilibrium condition of Fe-rich phase crystallizing into steady β-Fe phase is broken, and the metastable α-Fe phase is more easily formed.

       

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