Abstract—

The effect of manganese on the microstructure, phase composition, and mechanical properties of the heat-strengthened deformed Al–5.5Cu–2.0Y–0.3Zr alloy has been studied in this work. The structure of the cast alloy was shown to contain a quaternary phase enriched in copper, manganese, and yttrium with a Cu/Mn/Y ratio of 4/2/1, which corresponds to the chemical compound Al₂₅Cu₄Mn₂Y. The maximum strengthening of the ingot was achieved by aging after quenching at 210°C for 5 h. Three types of precipitates, Al₂₀Cu₂Mn₃ and Al₃(Zr,Y), were formed in the heat-treated structure in the course of homogenization at 605°C. The size of Al₃(Zr,Y) particles was 30–50 nm. The Al₂₀Cu₂Mn₃ phase had a longitudinal size of 200–250 nm and a transverse size of 150–200 nm. The disc-shaped precipitates of the θ''(Al₂Cu) metastable phase with a diameter of 80–200 nm and a thickness of about 5 nm formed upon aging. After rolling and annealing for 1 and 2 h, the hardness was maximum at 150°C. This was explained by a predominance of aging over softening, which retards the growth of dispersoids of Al₂₀Cu₂Mn₃ and Al₃(Zr,Y) phases and dispersed Al₈Cu₄Y and (Al,Cu)₁₁Y₃ particles of crystallization origin. At 210°C, the softening of deformed alloy prevails over the effect of aging and as a result, the hardness decreases slightly. The addition of manganese makes it possible to retain a significantly high hardness in the studied alloy at annealing temperatures up to 550°С and to increase the temperature of the onset of recrystallization to 350–400°С. After rolling followed by annealing at 150°C the alloy was shown to possess high mechanical properties: σ_0.2 = 330–334 MPa, σ_u = 374 MPa, and δ = 3.6–5.5%.

中文翻译：

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Mn对Al-Cu-Y-Zr合金相组成和性能的影响

摘要—

在这项工作中，研究了锰对热强化变形Al–5.5Cu–2.0Y–0.3Zr合金的组织，相组成和力学性能的影响。铸造合金的结构显示出含有季相在铜，锰富集和钇与4/2/1一个铜/锰/ Y比，其对应于化学化合物A1 ₂₅的Cu ₄的Mn ₂ Y.通过在210°C淬火5小时后进行时效处理，实现了铸锭的最大强化。在605℃下均质化的过程中，在热处理结构中形成三种类型的沉淀物，即Al ₂₀ Cu ₂ Mn ₃和Al ₃（Zr，Y）。Al ₃的大小（Zr，Y）粒子为30–50 nm。Al ₂₀ Cu ₂ Mn ₃相的纵向尺寸为200-250 nm，横向尺寸为150-200 nm。老化时形成直径为80-200 nm，厚度约5 nm的θ''（Al ₂ Cu）亚稳态相的圆盘状析出物。轧制并退火1和2小时后，硬度在150°C时最大。这主要是由老化而不是软化造成的，这阻碍了Al ₂₀ Cu ₂ Mn ₃和Al ₃（Zr，Y）相的弥散体的生长以及Al ₈ Cu ₄ Y和（Al，Cu）₁₁ Y _3的分散结晶起源的颗粒。在210°C时，变形合金的软化作用超过了时效，结果，硬度略有下降。锰的添加使得可以在高达550°С的退火温度下在所研究的合金中保持很高的硬度，并且可以将重结晶的起始温度提高到350-400°С。然后退火轧制在150℃后的合金被证明具有高的机械性能：σ _0.2 = 330-334兆帕，σ _û = 374兆帕，和δ= 3.6-5.5％。