【摘要】 通过力学性能测试、20℃电阻率测试及显微组织观察，研究了Si加入量为0.3wt%时对Al-1.5Cu-0.7Mg合金组织和性能的影响。结果表明，当Si加入量为0.3wt%时，Al-1.5Cu-0.7Mg合金时效态的强度明显提高，经473～493 K峰时效后，其20℃电阻率为3.638～3.667μΩ·cm,抗拉强度为370～380 MPa。根据马蒂森定律建立了20℃电阻率与时效析出第二相相对体积分数之间的关系式。利用JMA(Johnson-Mehl-Avrami)方程得出Al-1.5Cu-0.7Mg和Al-1.5Cu-0.7Mg-0.3Si合金的时效析出激活能分别为135 kJ/mol和204 kJ/mol,由此可判定，Al-1.5Cu-0.7Mg合金以S″相为主，Al-1.5Cu-0.7Mg-0.3Si合金以S相为主。由JMA方程对其他时效参数下的电阻率进行预测，预测模型的准确性在99%以上。更多还原

【Abstract】 Effect of 0.3wt%Si addition on the microstructure and mechanical properties of Al-1.5Cu-0.7Mg alloy was studied by means of mechanical test, resistivity test at 20 ℃ and microstructure observation. The results show that with the 0.3wt%Si addition, the as-aged strength of the tested alloy is obviously increased. After peak aging at 473-493 K, its 20 ℃ resistivity is 3.638-3.667 μΩ·cm, and its tensile strength is 370-380 MPa, and then the relationship between the 20 ℃ resistivity and the relative volume fraction of the second phase precipitated during aging is established according to Matthiessen rule. The second phase precipitation activation energies in aging of the Al-1.5Cu-0.7Mg and Al-1.5Cu-0.7Mg-0.3Si alloys obtained by using JMA(Johnson-Mehl-Avrami) equation are 135 kJ/mol and 204 kJ/mol respectively, according to which to know that the S″ phase is dominant in the Al-1.5Cu-0.7Mg alloy and the S phase is dominant in the Al-1.5Cu-0.7Mg-0.3Si alloy. The resistivity under other aging parameters is also predicted by JMA equation, and the accuracy of the prediction model is all over 99%.更多还原