In the present work, Zn–10Al–2Cu–0.05Ti (ZA10) alloy tubes with a diameter of 12.5 mm and wall thickness of 1.2 mm were fabricated by one-pass and double-pass Conform continuous extrusion. A stabilizing heat treatment [350 °C, 30 min (furnace cooling) + 120 °C, 12 h (air cooling)] was also applied to some of the double-pass tubes to improve the quality of their weld seams. The yield strength, ultimate tensile strength, elongation and expansion ratio of the one-pass continuous extrusion tube were 268.4 MPa, 294.3 MPa, 13.8% and 5.5%, respectively. Double-pass continuous extrusion improved these values to 278.4 MPa, 317.2 MPa, 15.4% and 11.4%, respectively. Double-pass tubes also had fewer aggregations of Al-α precipitates along the welding seam, which improved seam quality and caused cracks to appear in the matrix, away from the weld-affected zone, during expansion testing. Heat-treated double-pass tubes exhibited superior yield strength (283.9 MPa) and ultimate tensile strength (328.5 MPa) but lower elongation (10.2%) and expansion ratios (10.3%). Additionally, the heat-treated tubes exhibited markedly lower elongation at room temperature due to the remarkable blockage of dislocation motions by fine-scale lamellar (α + η) eutectoid structures and a lower size effect when stretched.

中文翻译：

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Conform连续挤压制备ZA10合金管及其焊缝的显微组织和力学性能

在目前的工作中，直径为 12.5 mm，壁厚为 1.2 mm 的 Zn-10Al-2Cu-0.05Ti (ZA10) 合金管通过单程和双程 Conform 连续挤压制造。还对一些双程管进行了稳定热处理 [350 °C，30 分钟（炉冷）+ 120 °C，12 小时（空冷）]，以提高其焊缝质量。一次连续挤压管的屈服强度、极限抗拉强度、伸长率和膨胀率分别为268.4 MPa、294.3 MPa、13.8%和5.5%。双程连续挤出将这些值分别提高到 278.4 MPa、317.2 MPa、15.4% 和 11.4%。双通管沿焊缝的Al-α析出物聚集较少，从而提高了焊缝质量并导致基体中远离焊缝影响区出现裂纹，在扩展测试过程中。热处理双通管表现出优异的屈服强度 (283.9 MPa) 和极限拉伸强度 (328.5 MPa)，但伸长率 (10.2%) 和膨胀率 (10.3%) 较低。此外，由于细尺度层状（α+η）共析结构对位错运动的显着阻塞以及拉伸时的较小尺寸效应，热处理管在室温下表现出显着较低的伸长率。