Scholarlink

<p>During solution aging treatment, aluminum alloy friction stir welding (FSW) joints are susceptible to abnormal grain development. The 5A06/2A97 FSW joints are the subject of this study, which examines the suppressing effect of cryogenic therapy on abnormal grain growth (AGG) in different joint zones during solution aging treatment. A systematic analysis of the effects of cryogenic treatment on the microstructural evolution, grain size distribution, and mechanical properties of 5A06/2A97 FSW joints was conducted using characterization techniques such as optical microscopy, microhardness testing, room-temperature tensile testing, and electron backscatter diffraction (EBSD). In comparison with joints that were directly subjected to solution aging treatment, the experiments showed that: On the 5A06 side, compared with direct solution aging treatment, the joints subjected to 24-hour cryogenic treatment followed by solution aging exhibited 14% and 42% reductions in grain size in the thermo-mechanically affected zone (TMAZ) and weld nugget zone (WNZ), respectively, though the hardness improvement was not significant. On the 2A97 side, the TMAZ and WNZ showed 46% and 36% reductions in grain size, respectively, along with a hardness increase of over 15% in both zones. After 24-hour cryogenic treatment, the joints achieved a tensile strength of 352&#xa0;MPa, yield strength of 210&#xa0;MPa, and elongation of 12%. The mechanism behind the suppression effect of cryogenic treatment on AGG was clarified by comparing the kernel average misorientation (KAM), precipitated phases, and grain size between the FSW joints treated with 24-hour cryogenic treatment and those not. In order to prevent AGG during solution aging treatment, cryogenic treatment increased the material’s internal dislocations and precipitated phases. This study proposes a novel approach to suppress AGG in FSW microstructures, which could expand post-weld processing techniques and enhance the microstructure and mechanical properties of FSW joints.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

The Inhibitory Effect of Cryogenic Treatment on Abnormal Grain Growth during Solution Aging Treatment of 5A06/2A97 Friction Stir Welding Joints

  • 期刊论文

  • 发表日期：

    2025年12月22日

查看全文
  • Zhonghuan Qin,
  • A. P. Wu,
  • Chunlai Zhang,
  • Baoyong Li,
  • Qi Liu,
  • Yue Zhao,
  • Hongliang Yin

摘要

During solution aging treatment, aluminum alloy friction stir welding (FSW) joints are susceptible to abnormal grain development. The 5A06/2A97 FSW joints are the subject of this study, which examines the suppressing effect of cryogenic therapy on abnormal grain growth (AGG) in different joint zones during solution aging treatment. A systematic analysis of the effects of cryogenic treatment on the microstructural evolution, grain size distribution, and mechanical properties of 5A06/2A97 FSW joints was conducted using characterization techniques such as optical microscopy, microhardness testing, room-temperature tensile testing, and electron backscatter diffraction (EBSD). In comparison with joints that were directly subjected to solution aging treatment, the experiments showed that: On the 5A06 side, compared with direct solution aging treatment, the joints subjected to 24-hour cryogenic treatment followed by solution aging exhibited 14% and 42% reductions in grain size in the thermo-mechanically affected zone (TMAZ) and weld nugget zone (WNZ), respectively, though the hardness improvement was not significant. On the 2A97 side, the TMAZ and WNZ showed 46% and 36% reductions in grain size, respectively, along with a hardness increase of over 15% in both zones. After 24-hour cryogenic treatment, the joints achieved a tensile strength of 352 MPa, yield strength of 210 MPa, and elongation of 12%. The mechanism behind the suppression effect of cryogenic treatment on AGG was clarified by comparing the kernel average misorientation (KAM), precipitated phases, and grain size between the FSW joints treated with 24-hour cryogenic treatment and those not. In order to prevent AGG during solution aging treatment, cryogenic treatment increased the material’s internal dislocations and precipitated phases. This study proposes a novel approach to suppress AGG in FSW microstructures, which could expand post-weld processing techniques and enhance the microstructure and mechanical properties of FSW joints.