Application and preparation method of copper-aluminum transitional composite connecting bar and multistage composite connecting bar

The invention relates to an application and a preparation method of a copper-aluminum transitional composite connecting bar and a longitudinal multistage connecting bar which belong to connecting materials in the field of power transmission. according to the invention, an ultra-thin copper substrate and an ultra-thin aluminum substrate are compounded through a detonating cord in an explosive welding way to form the connecting bar with the thickness less than 1mm, so that the connecting bar has good flexibility and good connecting performance, is easy to secondary shaping and cutting, has transitional conductive capability and is applicable to the embedded coil knuckle transitional connection in a curly state, transitional connection in a spiral winding mode, transitional connection of the substrate in a plane state, ectopic connection of a high-current line board and the like. The connecting bar can effectively solve the structural problems of a conventional longitudinal copper-aluminum transitional device, i