焊接速度对自反应摩擦搅拌焊制备的5251铝合金接头组织与力学性能的影响

Influence of Welding Speed on Microstructure and Mechanical Properties of 5251 Aluminum Alloy Joints Fabricated by Self-Reacting Friction Stir Welding.

作者信息

Gao Shikang, Zhou Li, Sun Guangda, Zhao Huihui, Chu Xiaolong, Li Gaohui, Zhao Hongyun

机构信息

State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, China.

Shandong Provincial Key Laboratory of Special Welding Technology, Harbin Institute of Technology at Weihai, Weihai 264209, China.

出版信息

Materials (Basel). 2021 Oct 18;14(20):6178. doi: 10.3390/ma14206178.

DOI:10.3390/ma14206178

PMID:34683767

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC8537164/

Abstract

In the present study, 8 mm-thick 5251 aluminum alloy was self-reacting friction stir welded (SRFSW) employing an optimized friction stir tool to analyze the effect of welding speed from 150 to 450 mm/min on the microstructure and mechanical properties at a constant rotation speed of 400 rpm. The results indicated that high-quality surface finish and defect-free joints were successfully obtained under suitable process parameters. The microhardness distribution profiles on the transverse section of joint exhibited a typical "W" pattern. The lowest hardness values located at the heat-affected zone (HAZ) and the width of the softened region decreased with increasing welding speed. The tensile strength significantly decreased due to the void defect, which showed mixed fracture characteristics induced by the decreasing welding speed. The average tensile strength and elongation achieved by the SRFSW process were 242.61 MPa and 8.3% with optimal welding conditions, and the fracture surface exhibited a typical toughness fracture mode.

摘要

在本研究中，采用优化的搅拌摩擦工具对8毫米厚的5251铝合金进行自反应搅拌摩擦焊（SRFSW），以分析在400转/分钟的恒定转速下，焊接速度从150毫米/分钟到450毫米/分钟对微观结构和力学性能的影响。结果表明，在合适的工艺参数下成功获得了高质量的表面光洁度和无缺陷接头。接头横截面上的显微硬度分布曲线呈现出典型的“W”形。最低硬度值位于热影响区（HAZ），且软化区域的宽度随焊接速度的增加而减小。由于气孔缺陷，抗拉强度显著降低，这表现出随着焊接速度降低而产生的混合断裂特征。在最佳焊接条件下，SRFSW工艺获得的平均抗拉强度和伸长率分别为242.61兆帕和8.3%，断口呈现出典型的韧性断裂模式。