降低均匀化温度对2024合金T3态组织和性能的影响

Effect of Decreasing Homogenization Temperature on Microstructure and Properties of 2024-T3 Alloy

摘要:

本文研究了降低均匀化温度对2024-T3态合金组织和性能的影响。结果表明：与工业化常规采用的490 ℃/24 h均匀化工艺相比，经430 ℃/24 h和460 ℃/24 h均匀化处理及轧制后，合金残留粗大第二相的面积分数接近且皆高于前者。由于粗大第二相的粒子激发形核（particle stimulated nucleation，PSN）效应，均匀化制度为430 ℃/24 h和460 ℃/24 h的合金在固溶淬火后再结晶分数更高且晶粒更为均匀细小。对3组合金进行硬度测试和拉伸试验，发现三者的峰值硬度、抗拉强度、屈服强度以及延伸率都比较接近。因此适当降低均匀化温度能够提高晶粒尺寸均匀性、降低生产成本，并且保持2024-T3态板材良好的拉伸性能；490 ℃/24 h的高温均匀化工艺可使T3态板材具有相对较好的塑韧性。

Abstract:

The effect of decreasing the homogenization temperature on the microstructure and mechanical properties of 2024-T3 alloy was investigated. The results show that the area fractions of the residual coarse secondary phases of alloys after homogenization at 430 or 460 ℃ for 24 h followed by rolling are similar, and they are higher than those of the alloys homogenized at 490 ℃ for 24 h. The latter treatment is routinely used in the industry. The alloys with homogenization of 430 ℃/24 h or 460 ℃/24 h and solution treatment have higher recrystallization fractions and finer grain sizes due to the particle stimulated nucleation (PSN) effect of the coarse secondary phase. Hardness tests and tensile tests show that the peak hardness, tensile strength, yield strength, and elongation of the three alloys are relatively similar to each other. Therefore, appropriately decreasing the homogenization temperature can improve the uniformity of grain size, reduce the cost, and maintain the excellent tensile properties of 2024-T3 plates. Whereas the high-temperature homogenization of 490 ℃/24 h can make the 2024-T3 sheet have relatively good plasticity and toughness.