Toward steel strip insertion during wire arc additive manufacturing of aluminum alloy smart part

Smart parts providing information to the user thanks to an embedded device are an important step toward the industry 4.0. Magneto-strictive properties of steel are well known and thin strips could be embedded in paramagnetic host part to ensure their structural control. Through this study, the feasibility of smarts parts realized by insertion of thin steel strip during aluminum host part manufacturing is more asserted. This study presents a configuration to embed thin steel strip inside massive part realized by Wire Arc Additive Manufacturing (WAAM). This configuration is used to find a correct steel strip - welding torch offset enabling a correct bonding between the deposited bead and the strip without causing any deterioration to the strip. Thickness maps of these strips realized through X-ray tomography allow to evaluate the deterioration of the strips. Scanning electron microscopy is used to evaluate the strength of the bonding through the thickness of the bimetallic interface realized between the steel strip and the aluminum bead. A good bonding between a thin steel strip and a thick part in aluminum alloy thanks to arc welding is obtained. The thickness difference between the two entities welded together represent a ratio of 10, which is 3 times bigger than the previous work reported in literature. Steel to aluminum welding is a challenging research topic and thin to thick element welding as well. This paper address both of these topics together and is a step toward smart metallic part manufacturing.