Microstructure evolution of Al/Mg butt joints welded by gas tungsten arc with Zn filler metal

Journal Article · Sun Jul 15 04:00:00 EDT 2012 · Materials Characterization

DOI:https://doi.org/10.1016/J.MATCHAR.2012.04.012· OSTI ID:22066472

Fei, Liu; Zhaodong, Zhang

Based on the idea of alloying welding seam, Gas tungsten arc welding method with pure Zn filler metal was chosen to join Mg alloy and Al alloy. The microstructures, phases, element distribution and fracture morphology of welding seams were examined. The results indicate that there was a transitional zone in the width of 80-100 {mu}m between the Mg alloy substrate and fusion zone. The fusion zone was mainly composed of MgZn{sub 2}, Zn-based solid solution and Al-based solid solution. The welding seam presented distinct morphology in different location owning to the quite high cooling rate of the molten pool. The addition of Zn metal could prevent the formation of Mg-Al intermetallics and form the alloyed welding seam during welding. Therefore, the tensile strengths of joints have been significantly improved compared with those of gas tungsten arc welded joints without Zn metal added. Highlights: Black-Right-Pointing-Pointer Mg alloy AZ31B and Al alloy 6061 are welded successfully. Black-Right-Pointing-Pointer Zinc wire is employed as a filler metal to form the alloyed welding seam. Black-Right-Pointing-Pointer An alloyed welding seam is benefit for improving of the joint tensile strength.

• OSTI ID: 22066472
• Journal Information: Materials Characterization, Journal Name: Materials Characterization Journal Issue: Complete Vol. 69; ISSN 1044-5803; ISSN MACHEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM BASE ALLOYS
FILLER METALS
FRACTURES
GAS TUNGSTEN-ARC WELDING
INTERMETALLIC COMPOUNDS
MAGNESIUM BASE ALLOYS
MICROSTRUCTURE
MORPHOLOGY
SOLID SOLUTIONS
SUBSTRATES
TENSILE PROPERTIES
TUNGSTEN
WELDED JOINTS
ZINC