Welding methods and welded joints for joining high-strength aluminum alloys
Welding methods and welded joints for improving corrosion resistance of the joint between a plurality of high-strength aluminum alloy structural members are described herein. An example method can include applying a first weld at a junction between the plurality of high-strength aluminum alloy structural members using a first filler metal, and applying a second weld on at least a portion of a toe of the first weld using a second filler metal. The second weld can be applied using a fusion welding process (e.g., an arc welding process or a high energy beam welding process). Additionally, the secondary weld can alter a secondary phase of the first weld.
1. A method for improving corrosion resistance of a welded joint between a plurality of high-strength aluminum alloy structural members, comprising:
applying a first weld at a junction between the plurality of high-strength aluminum alloy structural members using a first filler metal to join the plurality of high-strength aluminum alloy structural members, wherein the first weld is applied to each of the high-strength aluminum alloy structural members, wherein the first weld contacts respective surfaces of each of the high-strength aluminum alloy structural members, the first weld defining a toe along a line where the first weld meets the respective surface of at least one of the high-strength aluminum alloy structural members; and
applying a second weld on at least a portion of the toe of the first weld using a second filler metal,
wherein the second weld contacts at least a portion of the respective surface of the at least one of the high-strength aluminum alloy structural members and the portion of the toe of the first weld, wherein the second weld is applied using a fusion welding process, and wherein the second weld alters a secondary phase in the first weld.
2. The method of claim 1 , wherein the secondary phase in the first weld is anodic to at least one of the high-strength aluminum alloy structural members.
3. The method of claim 1 , wherein secondary phase precipitation at the toe of the first weld is reduced, minimized, eliminated, or isolated from a surface of the first weld, and secondary phase precipitation at a toe of the second weld is non-existent, or if existent, the secondary phase precipitation at the toe of the second weld is cathodic or neutral to at least one of the high-strength aluminum alloy structural members.
4. The method of claim 1 , wherein the second weld is applied after completion of the first weld or the first weld and the second weld are applied in tandem.
5. The method of claim 4 , wherein the second weld is applied after the first weld cools below a melting point of the first filler metal.
6. The method of claim 1 , wherein the second weld extends along an entire length of the toe of the first weld.
7. The method of claim 1 , wherein the plurality of high-strength aluminum alloy structural members comprise an aluminum (Al)-zinc (Zn) alloy or an Al-copper (Cu) alloy.
8. The method of claim 7 , wherein the plurality of high-strength aluminum alloy structural members are similar metals or dissimilar metals.
9. The method of claim 7 , wherein the Al—Zn alloy is a 7003 or 710.0 alloy and the Al—Cu alloy is a 2219 or a 201.0 alloy.
10. The method of claim 1 , wherein the plurality of high-strength aluminum alloy structural members comprise an Al-magnesium (Mg) alloy or an Al—Mg-silicon (Si) alloy.
11. The method of claim 1 , wherein the first filler metal comprises an Al—Mg alloy or an Al—Cu alloy.
12. The method of claim 11 , wherein the Al—Mg alloy is a 5356 or 5556 alloy and the Al—Cu alloy is a 2319 alloy.
13. The method of claim 1 , wherein the second filler metal comprises an Al—Si alloy, a commercially pure Al alloy, or an Al-manganese (Mn) alloy.
14. The method of claim 13 , wherein the Al—Si alloy is a 4043 or 4943 alloy, the commercially pure Al alloy is a 1100 or 1188 alloy, and the Al—Mn alloy is a 3103 alloy.
15. The method of claim 1 , wherein the fusion welding process comprises an arc welding process or a high energy beam welding process.
16. The method of claim 1 , wherein the first weld is applied using a fusion welding process.
17. The method of claim 1 , wherein the junction between the plurality of high-strength aluminum alloy structural members comprises at least one of a lap joint, a fillet joint, an edge joint, a corner joint, or a butt joint.
18. A method for improving corrosion resistance of a welded joint between a plurality of high-strength aluminum alloy structural members, comprising:
applying a first weld at a junction between the plurality of high-strength aluminum alloy structural members to join the plurality of high-strength aluminum alloy structural members, wherein the first weld is applied to each of the high-strength aluminum alloy structural members; and
applying a second weld on at least a portion of a surface of the first weld using a filler metal, wherein the second weld contacts a surface of at least one of the high-strength aluminum alloy structural members and the portion of the surface of the first weld, and wherein the second weld is applied using a fusion welding process.
19. The method of claim 18 , wherein the first weld is applied using a solid-state friction stir welding (FSW) process.
20. The method of claim 18 , wherein the first weld is applied using a fusion welding process.
21. The method of claim 18 , further comprising applying a plurality of second welds on at least respective portions of a surface of the first weld using the filler metal.
22. The method of claim 18 , wherein the junction between the plurality of high-strength aluminum alloy structural members comprises at least one of a lap joint, a fillet joint, an edge joint, a corner joint, or a butt joint.