Combined numerical and experimental estimation of the fracture toughness and failure analysis of single lap shear test for dissimilar welds

Jimenez-Mena, Norberto; Sapanathan, Thaneshan; Jacques, Pascal; Simar, Aude

doi:10.1016/j.engfracmech.2021.107756

Cited by 7 publications

(1 citation statement)

References 51 publications

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“…A reduced IML thickness ensures straining to occur in the more ductile base materials, allowing increased joint strength to be achieved. However the effect of IML thickness reduction is shown to be limited [3]. On the other hand, the discrepancy in resistivity and melting temperature between the materials as well as the high conductivity of copper cause a suboptimal heat balance during welding, whereby -depending on the material thicknesses used in the welding stack, melting often initiates in the bulk of the aluminium workpiece instead of at the dissimilar interface, or whereby local melting occurs at the electrode-workpiece interface, even in early stages of the welding process, leading to accelerated electrode wear.…”

Section: Introductionmentioning

confidence: 99%

Copper-aluminium joining by novel locked projection welding process

2023

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Leveraged by the transition to carbon neutrality, manufacturing industry shifts towards multi-material structures, combining material properties, optimising costs and enabling lightweight design. In automotive production, lightweight hybrid design reduces fuel consumption, hence the emission of greenhouse gasses. Amongst other measures, this is achieved by combining steel and aluminium alloys in body-in-white manufacturing, as well as using both copper and aluminium alloys for optimised weight, cost and performance of battery packs for electric vehicles. Albeit joining sheet-like components is often performed by costefficient resistance welding processes, robust dissimilar joining by these processes has proven to be a challenge due to discrepancies in physical and metallurgical properties. Multiple researchers have proposed improvements to resistance (spot) welding processes for highly dissimilar metal joining. These influence the growth rate, morphology and/or composition of the formed intermetallic compounds at the dissimilar metal interface, hereby aiming to improve the mechanical joint strength and altering the failure mode. However, the presented improvements still suffer from limited cross tension strength and/or brittle joint failure, especially for small-scale joints. In this work, a novel resistance welding process variant is presented, developed for joining material Copper-aluminium joining by novel locked projection welding process combinations with a highly dissimilar melting temperature. By complementing the metallurgic joint with a mechanical connection, the presented locked projection welding technique is designed to yield ductile joint failure opposed to the brittle failure that characterises such dissimilar resistance spot welds. The novel welding process is validated on a copper-aluminium material combination and compared to resistance spot welds based on joint morphology and mechanical properties.

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Section: Introductionmentioning

confidence: 99%