Abstract

The effect of iron and silicon impurities on the phase composition and properties of the Al–4.3Cu–2.2Yb quasi-binary alloy has been determined. In the microstructure of the cast alloy, in addition to the aluminum solid solution and dispersed eutectic ((Al) + Al₈Cu₄Yb), in which about 1% of iron is dissolved, the Al₃Yb/(Al,Cu)₁₇Yb₂ and Al₈₀Yb₅Cu₆Si₈ phases are identified, which are not found in an alloy of a similar composition without impurities. After homogenization annealing at a temperature of 590°C for 3 h, the structure is represented by compact fragmented and coagulated intermetallic compounds 1–2 μm in size and a solid solution (Al) with a maximum copper content of 2.1%. The hardness of the deformed sheets significantly decreases after 0.5 h and changes slightly up to 6 h of annealing at temperatures of 150–210°C. After annealing at 180°C for 3 h, a substructure with a subgrain size of 200–400 nm is formed in the alloy structure. The softening after annealing of the rolled sheets at temperatures up to 250°C occurs owing to the recovery and polygonization processes and above 300°C owing to recrystallization. After annealing for 1 h at 300°C, the recrystallized grain size is 7 μm. The grain size increases to 16 µm after annealing for 1 h at 550°C. The Al–4.3Cu–2.2Yb alloy with impurities has a conditional yield strength of 205–273 MPa, a tensile strength of 215–302 MPa, and a relative elongation of 2.3–5.6% in the rolled alloy after annealing. Iron and silicon impurities do not lead to the formation of coarse lamellar intermetallic phases and do not reduce the ductility of the investigated alloy.

中文翻译：

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含铁和硅杂质的Al-Cu-Yb合金的组织与性能

摘要

已经确定了铁和硅杂质对 Al-4.3Cu-2.2Yb 准二元合金的相组成和性能的影响。在铸造合金的显微组织中，除了固溶铝和弥散共晶((Al)+Al ₈ Cu ₄ Yb)，其中溶解了约1%的铁，Al ₃ Yb/(Al,Cu) ₁₇ Yb ₂和 Al ₈₀ Yb ₅ Cu ₆ Si ₈相被识别，这在没有杂质的类似成分的合金中是找不到的。在 590°C 的温度下均匀化退火 3 小时后，该结构由尺寸为 1-2 μm 的致密碎裂和凝聚的金属间化合物和最大铜含量为 2.1% 的固溶体 (Al) 表示。变形板材的硬度在 0.5 小时后显着降低，并且在 150–210°C 的温度下退火 6 小时后略有变化。在180℃退火3 h后，合金结构中形成亚晶粒尺寸为200-400 nm的亚结构。在高达 250°C 的温度下轧制板退火后软化是由于恢复和多角化过程而发生的，而在 300°C 以上的温度下由于再结晶而发生软化。300℃退火1 h后，再结晶晶粒尺寸为7 μm。在 550°C 退火 1 小时后，晶粒尺寸增加到 16 µm。含杂质的Al-4.3Cu-2.2Yb合金退火后轧制合金的条件屈服强度为205～273 MPa，抗拉强度为215～302 MPa，相对伸长率为2.3～5.6%。铁和硅杂质不会导致粗层状金属间相的形成，也不会降低所研究合金的延展性。