Study on Microstructure and Fatigue Damage Mechanism of 6061 Aluminum Alloy Laser-Metal Inert Gas Hybrid Welding

IF 2 4区材料科学 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Materials Engineering and Performance Pub Date : 2025-03-24 DOI:10.1007/s11665-025-11001-2

Qiubo Li, Shanglei Yang, Bangguo Hu, Suqi Xue, Cong Fan

{"title":"Study on Microstructure and Fatigue Damage Mechanism of 6061 Aluminum Alloy Laser-Metal Inert Gas Hybrid Welding","authors":"Qiubo Li, Shanglei Yang, Bangguo Hu, Suqi Xue, Cong Fan","doi":"10.1007/s11665-025-11001-2","DOIUrl":null,"url":null,"abstract":"<div><p>6061 aluminum alloy is widely utilized in the automotive, high-speed rail, aerospace, and various other sectors due to its excellent corrosion resistance, weldability, and outstanding formability. In recent years, laser-arc hybrid welding has emerged as a novel technology for aluminum alloy welding, making it essential to investigate the fatigue properties of welded joints. In this paper, 6061 aluminum alloy plate with thickness of 4mm was welded by laser-MIG hybrid welding technology. Optical microscope observations reveal that the upper and lower regions of the hybrid welded joint are influenced by the laser-MIG arc and the single laser, respectively. The energy density and heat input differ between the two, resulting in a smaller equiaxed grain size in the upper part of the weld compared to the lower part. The fatigue limit of the 6061 aluminum alloy welded joint, determined through fatigue testing and S-N curve analysis, is 79.1 MPa for 10<sup>6</sup> cycles. Under cyclic loading with stress amplitudes (<i>σ</i><sub>a</sub>) of 95 MPa and 115 MPa, the fatigue crack initiation sites are located in the sub-surface of the specimens, which contain pores. The fatigue fractures under different stress amplitudes show ductile fracture characteristics.</p></div>","PeriodicalId":644,"journal":{"name":"Journal of Materials Engineering and Performance","volume":"34 20","pages":"23452 - 23462"},"PeriodicalIF":2.0000,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Materials Engineering and Performance","FirstCategoryId":"88","ListUrlMain":"https://link.springer.com/article/10.1007/s11665-025-11001-2","RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}

引用次数: 0

Abstract

6061 aluminum alloy is widely utilized in the automotive, high-speed rail, aerospace, and various other sectors due to its excellent corrosion resistance, weldability, and outstanding formability. In recent years, laser-arc hybrid welding has emerged as a novel technology for aluminum alloy welding, making it essential to investigate the fatigue properties of welded joints. In this paper, 6061 aluminum alloy plate with thickness of 4mm was welded by laser-MIG hybrid welding technology. Optical microscope observations reveal that the upper and lower regions of the hybrid welded joint are influenced by the laser-MIG arc and the single laser, respectively. The energy density and heat input differ between the two, resulting in a smaller equiaxed grain size in the upper part of the weld compared to the lower part. The fatigue limit of the 6061 aluminum alloy welded joint, determined through fatigue testing and S-N curve analysis, is 79.1 MPa for 10⁶ cycles. Under cyclic loading with stress amplitudes (σ_a) of 95 MPa and 115 MPa, the fatigue crack initiation sites are located in the sub-surface of the specimens, which contain pores. The fatigue fractures under different stress amplitudes show ductile fracture characteristics.

查看原文本刊更多论文

6061铝合金激光-金属惰性气体复合焊接组织及疲劳损伤机理研究

6061铝合金具有优异的耐腐蚀性、可焊性和优异的成形性，广泛应用于汽车、高铁、航空航天等领域。近年来，激光-电弧复合焊接作为一种新兴的铝合金焊接技术，对焊接接头的疲劳性能进行研究是十分必要的。采用激光- mig复合焊接技术对厚度为4mm的6061铝合金板进行焊接。光学显微镜观察发现，激光- mig电弧和单激光分别对混合焊接接头的上部和下部产生影响。两者之间的能量密度和热输入不同，导致焊缝上部的等轴晶粒尺寸比下部小。通过疲劳试验和S-N曲线分析，确定6061铝合金焊接接头106次循环的疲劳极限为79.1 MPa。在应力幅值（σa）为95 MPa和115 MPa的循环加载下，试样的疲劳裂纹萌生部位位于含孔隙的次表面；不同应力幅值下的疲劳断口均表现出韧性断裂特征。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Journal of Materials Engineering and Performance 工程技术-材料科学：综合

CiteScore

3.90

自引率

13.00%

发文量

1120

审稿时长

4.9 months

期刊介绍： ASM International''s Journal of Materials Engineering and Performance focuses on solving day-to-day engineering challenges, particularly those involving components for larger systems. The journal presents a clear understanding of relationships between materials selection, processing, applications and performance. The Journal of Materials Engineering covers all aspects of materials selection, design, processing, characterization and evaluation, including how to improve materials properties through processes and process control of casting, forming, heat treating, surface modification and coating, and fabrication. Testing and characterization (including mechanical and physical tests, NDE, metallography, failure analysis, corrosion resistance, chemical analysis, surface characterization, and microanalysis of surfaces, features and fractures), and industrial performance measurement are also covered