Abstract

The study investigates the effectiveness of a novel joint configuration, the double-butt-lap (DBL), in friction stir welding (FSW) to join 6-mm-thick AA 6061-T6 plates. Four welds, including a simple square butt (SSB) configuration and three DBL variations (with UB to LB ratios of 1:2, 1:1, and 2:1), were executed. Using consistent parameters, the investigation evaluates the force distribution, macrostructure, and mechanical properties of the joints. Results show varied force profiles; spindle torque and Z-force decrease notably in DBL configurations compared to SSB, while X-force decreases overall for all DBL variations. Macrostructural analysis indicates increased weld area and finer microstructures in DBL joints. A correlation between peak temperature, grain size, and hardness highlights larger grain sizes at higher temperatures, influencing joint hardness. The DBL configuration with a 2:1 ratio exhibits the highest joint efficiency (83.76%). Fractographic analysis indicates ductile failure in all samples. Bend testing reveals increased flexural strength and bend angles in two DBL-configured joints compared to SSB. The results indicate that using a 2:1 ratio for joining 6-mm AA6061-T6 plates through FSW is viable, providing valuable insights into enhancing mechanical properties by optimizing joint geometry.

中文翻译：

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通过定制的双对接搭接几何形状提高搅拌摩擦焊的接头性能

摘要

该研究调查了新型接头配置双对接搭接 (DBL) 在搅拌摩擦焊 (FSW) 中连接 6 毫米厚 AA 6061-T6 板的有效性。执行了四种焊接，包括简单的方形对接 (SSB) 配置和三种 DBL 变体（UB 与 LB 的比例为 1:2、1:1 和 2:1）。使用一致的参数，研究评估了接头的力分布、宏观结构和机械性能。结果显示不同的力分布；与 SSB 相比，DBL 配置中的主轴扭矩和 Z 力显着下降，而所有 DBL 变体的 X 力总体下降。宏观结构分析表明 DBL 接头的焊接面积增加，微观结构更精细。峰值温度、晶粒尺寸和硬度之间的相关性凸显了较高温度下较大的晶粒尺寸，从而影响接头硬度。比例为 2:1 的 DBL 配置表现出最高的接头效率 (83.76%)。断口分析表明所有样品均出现延展性破坏。弯曲测试表明，与 SSB 相比，两个 DBL 配置接头的弯曲强度和弯曲角度有所提高。结果表明，使用 2:1 的比例通过 FSW 连接 6 毫米 AA6061-T6 板是可行的，为通过优化接头几何形状来增强机械性能提供了宝贵的见解。