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通过微观观察和拉伸测试的手段,对比研究了在一种高Cu/Li比的新型Al-5.8Cu-1.3Li合金(质量分数,%)中分别加入Ce,Zr或者两者共同添加对其合金微观组织与力学性能的影响。微观观察表明:Ce和Zr共同添加合金与单一添加Ce或者Zr的合金比较,金属间化物弥散体由粗大的多边形颗粒转变成无规则的细小粒子,相应的拉伸断口断裂模式由脆性的沿晶断裂向塑性穿晶断裂转变。进一步微观分析表明:Ce的添加促进了Al-Cu-Li合金中主要强化相T1的析出。Ce和Zr共同添加合金与单一添加Ce合金相比,由于相对较少的Cu被束缚在尺寸较小的AlC uC e弥散体中,该合金基体中的Cu过饱和度在固溶淬火后相对更高。因此,Al-Cu-Li-Ce-Zr合金与Al-Cu-Li-Ce合金相比较,其析出相种类向T1转变,尺寸变得更小,晶粒更加细化,从而导致了该合金在峰时效时抗拉强度和屈服强度分别相对提高了19.6%和16.1%,并具有与之相当的延伸率。
By means of microscopic observation and tensile test, we compare the addition of Ce and Zr into a new Al-5.8Cu-1.3Li alloy with high Cu / Li ratio (mass fraction,%) Effect of Alloy Microstructure and Mechanical Properties. The microscopic observation shows that the intermetallic compounds disperse from coarse polygons to irregular small particles, and the corresponding tensile fracture mode is composed of brittle grains along with the addition of Ce and Zr to the alloys with addition of Ce or Zr. Fracture to plastic transgranular fracture transformation. Further microscopic analysis shows that the addition of Ce promotes the precipitation of the main strengthening phase T1 in the Al-Cu-Li alloy. Ce and Zr Co-addition Compared to a single addition of Ce, Cu supersaturation in this alloy matrix is relatively more after solution-quenching due to the relatively small amount of Cu bound in the smaller AlCuC dispersion high. Therefore, compared with the Al-Cu-Li-Ce alloy, the Al-Cu-Li-Ce-Zr alloy changes its precipitation type to T1, the size becomes smaller and the crystal grains become finer. As a result, The tensile strength and yield strength at peak aging were increased by 19.6% and 16.1%, respectively, with comparable elongation.