Prestrain and Aging Treatment to Improve the Mechanical Properties of AA6022 Aluminum Alloy Laser Weldment
Prestrain and Aging Treatment to Improve the Mechanical Properties of AA6022 Aluminum Alloy Laser Weldment
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DOI：
10.1007/s11661-009-9965-3
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发表时间：
2009-11-01
影响因子：
2.8
通讯作者：
Lin, C. C.
中科院分区：
文献类型：
--
作者：
Lin, H. C.;Kuo, T. Y.;Lin, C. C.
为提高铝合金薄板激光焊接件的力学性能，进行了激光焊接工艺研究.模拟板料成形，对母材及其Nd：YAG激光焊接件施加不同的拉伸预应变;然后，对一些样品进行油漆-烘烤-循环（PBC）处理，对一些样品进行175 ℃/1000分钟的人工时效处理。进行拉伸试验和维氏硬度试验，然后进行透射电子显微镜（TEM），能量色散谱（EDS），和电子探针显微分析（EPMA）进行了研究的微观结构和成分。结果表明，拉伸预应变和热处理条件影响力学性能的不同强化机制有关。与传统车身覆盖件生产的PBC工艺相比，焊件经过175 ° C/ 1000 min人工时效处理后，通过其沉淀强化机制，可以显着提高屈服强度和硬度。该操作过程还减少了母材和焊件之间的性能失配。虽然焊件的延伸率通常低于母材，但可以在焊件上成功地进行板成形工艺（作为预应变），同时为车身覆盖件留下一定的延伸能力。因此，本文提出的焊件时效处理是一种很有前途的技术。
This study aimed to improve the mechanical properties of aluminum alloy sheet laser weldments. Different tensile prestrains, which simulate sheet forming, were applied to a base metal and its Nd:YAG laser weldment, respectively; then, some samples were subjected to a paint-bake-cycling (PBC) process and some samples were subjected to an artificial aging treatment of 175 degrees C/1000 min. The tensile test and Vickers hardness test, followed by transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDS), and electron-probe microanalysis (EPMA), were applied to examine the microstructures and compositions. The results showed that tensile prestrain and heat-treatment conditions affect the mechanical properties in relation to the different strengthening mechanisms involved. Compared to traditional PBC processes of auto-body panel production, a weldment applied with an artificial aging treatment at 175 degrees C/ 1000 min could significantly improve the yield strength and hardness through its precipitation strengthening mechanism. This operation process also reduces the property mismatch between the base metal and weldment. Although the elongation ratio of the weldment is typically inferior to the base metal, the sheet forming process (as prestrain) can be operated on the weldment successfully, while leaving some elongation capability for auto-body panel. Therefore, the proposed aging treatment for the weldment provided in this article is a promising technique.