Tohoku University Technology: Joining of Solid Metals: T24-079
It is possible to strongly bond phase-separated metals that could not be traditionally metallurgically joined while maintaining the shape of the components.
The technology for joining dissimilar metals is expected to contribute to weight reduction of vehicles such as automobiles, railways, and aircraft, improving safety and speed performance, as well as reducing CO2 emissions through lightweighting. However, depending on the types of metals, compatibility issues can arise, leading to phase separation and making joining difficult. The inventors developed a method for joining incompatible metals, such as Fe and Mg, using the de-alloying method as described in Patent No. 6710707. By pre-diffusion bonding an Fe-Ni intermediate layer to the tip of the Fe, and then heating the Fe-Ni intermediate layer in contact with Mg, de-alloying occurred. Only Ni was de-alloyed from the intermediate layer to the Mg side, and Mg filled the gaps in the porous structure of Fe, resulting in a composite structure where Fe and Mg were intertwined at the joint interface, achieving a strong Fe-Mg mechanical bond. Additionally, by utilizing the decrease in melting temperature associated with the Mg-Ni alloy reaction, the joint interface could be liquefied while maintaining the shape of the joined materials, thereby promoting de-alloying. At the same time, pressure was continuously applied to expel the alloy liquid, which becomes brittle upon solidification, to the outside.
- Company：Tohoku Techno Arch Co., Ltd.
- Price：Other
