Microstructure and Mechanical Properties of High-Strength AA6011 Aluminum Alloy Welding with Novel 4xxx Filler Metals
Welding high-strength 6xxx aluminum alloys using a commercial ER4043 filler often results in inferior joint strength. This study investigated the effects of newly developed Al-Si-Mg filler metals with varying Mg (0.6–1.4 wt.%) and Mn (0.25–0.5 wt.%) contents on the microstructure evolution and mecha...
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| Format: | Article |
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MDPI AG
2024-01-01
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| Online Access: | https://www.mdpi.com/1996-1944/17/2/380 |
| _version_ | 1797343098968211456 |
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| author | Mohamed Ahmed Mousa Javidani Alexandre Maltais X.-Grant Chen |
| author_facet | Mohamed Ahmed Mousa Javidani Alexandre Maltais X.-Grant Chen |
| author_sort | Mohamed Ahmed |
| collection | DOAJ |
| description | Welding high-strength 6xxx aluminum alloys using a commercial ER4043 filler often results in inferior joint strength. This study investigated the effects of newly developed Al-Si-Mg filler metals with varying Mg (0.6–1.4 wt.%) and Mn (0.25–0.5 wt.%) contents on the microstructure evolution and mechanical performance of high-strength AA6011-T6 plates using gas metal arc welding. Two commercial fillers, ER4043 and ER4943, were used as references for comparison. The results revealed that increasing the Mg and Mn contents in the novel fillers resulted in sufficiently high alloying elements in the fusion zone (FZ), leading to higher microhardness. Under as-welded conditions, the weakest region of the joint was the heat-affected zone (HAZ). The joint strength was almost independent of the filler type and was controlled by the HAZ strength, measuring a UTS of 230 and 241 MPa for ER4043 and the other joints, respectively. The higher Mg contents in the novel fillers promoted the precipitation of a large volume fraction of fine β″-MgSi in the FZ during post-weld heat treatment (PWHT), resulting in superior strength and higher welding efficiency relative to the reference fillers. The optimal Mg content of the novel fillers was 0.6 wt.%. Increasing the Mn content of the filler metal had an insignificant effect. The FMg0.6 filler with 0.6% Mg achieved the best combination of strength (UTS of 410 MPa) and elongation (6.7%) as well as the highest welding efficiency (94%) after PWHT, among all of the fillers studied. However, the newly developed fillers adversely affected the impact toughness of the joints. |
| first_indexed | 2024-03-08T10:43:48Z |
| format | Article |
| id | doaj.art-e4506c64c43b4efe909ff4d5882c9a19 |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-08T10:43:48Z |
| publishDate | 2024-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Materials |
| spelling | doaj.art-e4506c64c43b4efe909ff4d5882c9a192024-01-26T17:27:03ZengMDPI AGMaterials1996-19442024-01-0117238010.3390/ma17020380Microstructure and Mechanical Properties of High-Strength AA6011 Aluminum Alloy Welding with Novel 4xxx Filler MetalsMohamed Ahmed0Mousa Javidani1Alexandre Maltais2X.-Grant Chen3Department of Applied Science, University of Québec at Chicoutimi, Saguenay, QC G7H 2B1, CanadaDepartment of Applied Science, University of Québec at Chicoutimi, Saguenay, QC G7H 2B1, CanadaArvida Research and Development Center, Rio Tinto Aluminum, Saguenay, QC G7S 4K8, CanadaDepartment of Applied Science, University of Québec at Chicoutimi, Saguenay, QC G7H 2B1, CanadaWelding high-strength 6xxx aluminum alloys using a commercial ER4043 filler often results in inferior joint strength. This study investigated the effects of newly developed Al-Si-Mg filler metals with varying Mg (0.6–1.4 wt.%) and Mn (0.25–0.5 wt.%) contents on the microstructure evolution and mechanical performance of high-strength AA6011-T6 plates using gas metal arc welding. Two commercial fillers, ER4043 and ER4943, were used as references for comparison. The results revealed that increasing the Mg and Mn contents in the novel fillers resulted in sufficiently high alloying elements in the fusion zone (FZ), leading to higher microhardness. Under as-welded conditions, the weakest region of the joint was the heat-affected zone (HAZ). The joint strength was almost independent of the filler type and was controlled by the HAZ strength, measuring a UTS of 230 and 241 MPa for ER4043 and the other joints, respectively. The higher Mg contents in the novel fillers promoted the precipitation of a large volume fraction of fine β″-MgSi in the FZ during post-weld heat treatment (PWHT), resulting in superior strength and higher welding efficiency relative to the reference fillers. The optimal Mg content of the novel fillers was 0.6 wt.%. Increasing the Mn content of the filler metal had an insignificant effect. The FMg0.6 filler with 0.6% Mg achieved the best combination of strength (UTS of 410 MPa) and elongation (6.7%) as well as the highest welding efficiency (94%) after PWHT, among all of the fillers studied. However, the newly developed fillers adversely affected the impact toughness of the joints.https://www.mdpi.com/1996-1944/17/2/380high-strength aluminum alloy weldingAA6011 alloy4xxx filler metalsmechanical propertiesimpact toughness |
| spellingShingle | Mohamed Ahmed Mousa Javidani Alexandre Maltais X.-Grant Chen Microstructure and Mechanical Properties of High-Strength AA6011 Aluminum Alloy Welding with Novel 4xxx Filler Metals Materials high-strength aluminum alloy welding AA6011 alloy 4xxx filler metals mechanical properties impact toughness |
| title | Microstructure and Mechanical Properties of High-Strength AA6011 Aluminum Alloy Welding with Novel 4xxx Filler Metals |
| title_full | Microstructure and Mechanical Properties of High-Strength AA6011 Aluminum Alloy Welding with Novel 4xxx Filler Metals |
| title_fullStr | Microstructure and Mechanical Properties of High-Strength AA6011 Aluminum Alloy Welding with Novel 4xxx Filler Metals |
| title_full_unstemmed | Microstructure and Mechanical Properties of High-Strength AA6011 Aluminum Alloy Welding with Novel 4xxx Filler Metals |
| title_short | Microstructure and Mechanical Properties of High-Strength AA6011 Aluminum Alloy Welding with Novel 4xxx Filler Metals |
| title_sort | microstructure and mechanical properties of high strength aa6011 aluminum alloy welding with novel 4xxx filler metals |
| topic | high-strength aluminum alloy welding AA6011 alloy 4xxx filler metals mechanical properties impact toughness |
| url | https://www.mdpi.com/1996-1944/17/2/380 |
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