【摘要】 采用双流浇注连续铸造方法获得了在过渡层上具有宏观成分梯度分布的2024/3003铝合金。通过组织观察和力学性能测试研究了该合金高温退火后的组织和性能变化。结果表明,2024/3003铝合金经480℃高温退火后,内层合金的洛氏硬度比铸态时的大幅提高,但随退火时间的延长,硬度的增幅很小,这种硬度变化是由于合金元素在α基体中固溶强化引起的。外层合金的硬度随退火时间的延长则明显降低,这是由于基体组织发生了再结晶和晶粒长大,而合金的固溶强化效果有限;高温退火对2024/3003合金的宏观成分梯度分布影响很小。更多还原

【Abstract】 The 2024/3003 aluminum alloy ingot with macro-scale gradient distribution of composition in transition layer was prepared by double-stream-pouring continuous casting.The evolution of the microstructure and properties of the alloy annealed at high temperature was investigated.The results show that the Rockwell hardness in the internal layer of the alloy increases significantly comparing with that of the as-cast alloy after annealing at 480 ℃.However,there is little increase of Rockwell hardness with the prolonging of annealing time.This occurrence is attributed to the solution strengthening of the alloy element in α(Al) matrix.While the hardness in the external layer of the alloy after annealing decreases obviously with the prolonging of annealing time due to the recrystalization,growth of the α(Al) grain and relatively weak effect of the solution strengthening.The results also show that the macro-scale composition gradient distribution of 2024/3003 alloy is not effected much by high temperature annealing.更多还原