Interface microstructure and tensile properties of a third generation aluminium-steel butt weld produced using the Hybrid Metal Extrusion & Bonding (HYB) process

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:809

Article

Sandnes, Lise¹  Bergh, Tina²  Grong, Oystein^1,3  Holmestad, Randi²  Vullum, Per Erik^2,4  Berto, Filippo¹ 

[1] Norwegian Univ Sci & Technol NTNU, Dept Mech & Ind Engn, Richard Birkelands Vei 2b, N-7491 Trondheim, Norway

[2] NTNU, Dept Phys, Hgsk Ringen 5, N-7491 Trondheim, Norway

[3] HyBond AS, NAPIC, Richard Birkelands Vei 2b, N-7491 Trondheim, Norway

[4] SINTEF Ind, Dept Mat & Nanotechnol, Hgsk Ringen 5, N-7491 Trondheim, Norway

关键词: Hybrid Metal Extrusion & Bonding;    Aluminum-steel welding;    Tensile testing;    Digital image correlation;    Intermetallic phases;    Transmission electron microscopy;   

DOI  :  10.1016/j.msea.2021.140975

来源: Elsevier

【 摘 要 】

The Hybrid Metal Extrusion & Bonding (HYB) process is a patented solid state joining method for metals which utilizes filler material additions to consolidate the weld. In the present investigation the interface microstructure and tensile properties of a 4 mm thick joint, belonging to the third generation Al-steel HYB butt welds, are characterized. The mechanical testing shows that the HYB weld exhibits excellent tensile properties, displaying ultimate tensile strength values in the range from 238 to 266 MPa. Moreover, supplementary digital image correlation analysis of the strain evolution occurring during tensile testing reveals that all plastic deformation is localized to the soft heat-affected zone on the aluminium side of the joint, leading to necking and final fracture in the aluminium. Scanning and transmission electron microscopy examinations of the Al-steel interface show that bonding occurs by a combination of microscale mechanical interlocking and intermetallic compound formation. The intermetallic layer has a thickness varying between 0.1 and 1 ?m and is composed of Al?Fe?Si crystals. This makes the butt joint highly resistant against interfacial cracking. The subsequent benchmarking against com-mercial fusion and solid state welding methods reveals that the tensile properties of the Al-steel HYB weld even surpass those reported for comparable friction stir welds. At the same time, the HYB process allows butt welding to be performed at much higher speeds compared to friction stir welding, without compromising the mechanical

【 授权许可】

Free