Mechanical and microstructural behavior of friction stir welded similar and dissimilar sheets of AA2219 and AA7475 aluminium alloys
Mechanical and microstructural behavior of friction stir welded similar and dissimilar sheets of AA2219 and AA7475 aluminium alloys
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DOI：
10.1016/j.jallcom.2016.11.389
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发表时间：
2017-02
影响因子：
6.2
通讯作者：
Noor Zaman Khan;A. N. Siddiquee;Z. Khan;A. K. Mukhopadhyay
中科院分区：
文献类型：
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作者：
Noor Zaman Khan;A. N. Siddiquee;Z. Khan;A. K. Mukhopadhyay
采用搅拌摩擦焊工艺对2.5mm厚的AA 2219-O和AA 7475-T761铝合金板进行了焊接。AA 2219和AA 7475铝合金分别用于航天飞机和航空器的部件中，这需要有效的制造工艺。搅拌摩擦焊是一种清洁的焊接工艺，能够连接难以焊接的航空铝合金。对搅拌摩擦焊接头的拉伸性能、显微组织、显微硬度和断口形貌进行了分析。由于剧烈塑性变形引起的动态再结晶，在搅拌区观察到晶粒细化。观察到异种接头的最低强度主要是由于机械和物理性能差异导致的基材的不均匀移动。由于热软化，所有接头的TMAZ后退侧硬度最低。相似接头的断裂表面比异种接头表现出更多的韧性断裂，这导致异种接头的伸长率较低。
Friction stir welding process has been employed to join similar and dissimilar 2.5 mm thick sheets of AA2219-O and AA 7475-T761 aluminium alloys. AA2219 and AA7475 Al alloys are utilized in the components of space shuttles and aircraft, respectively that require efficient fabrication process. Friction stir welding is a clean welding process capable of joining difficult to weld aerospace aluminium alloys. Tensile properties, microstructure, micro-hardness, and fracture surfaces of the friction stir welded joints were analyzed. Grain refinement is observed at the stir zone due to dynamic recrystallization caused by severe plastic deformation. Lowest strength for dissimilar joint is observed primarily due to non homogeneous movement of base materials consequent to differences in mechanical and physical properties. Minimum hardness was found at TMAZ retreating side for all joints due to the thermal softening. Fractured surfaces of the similar joints showed more ductile fracture compared to dissimilar joint which resulted in lower elongation of the dissimilar joints.