Twist compression welding of aluminum.

Numerical Modeling of the Transient Liquid-phase Diffusion Bonding Process of Al Using Cu Filler Metal

“…From these balance equations, the liquid width, W, can be determined as follows: (10) where cosq 1 and r are determined from Eqs. (7), (8) and (9) and are precise values of the surface energy and the interface energy. s S , s L and s I are required to calculate the value of cosq 1 .…”

“…1,2) However, it is well known that diffusion bonding between aluminum alloys is difficult due to the stability of surface oxide films at the bonding interface. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] In order to produce a sound joint, the surface oxide film must be removed from the bonding interface. There are two diffusion bonding techniques: solid-state diffusion bonding and transient liquid-phase (TLP) diffusion bonding.…”

“…In the solid-state diffusion bonding process, brittle and continuous oxide films can be removed by imposing a friction force on the bonding interface. 8,9) Strong joints have been made in the solid state between aluminum alloys containing lithium, magnesium and zinc as alloying additions, which render the surface oxide films less stable. 10) In the TLP diffusion bonding process, a filler metal (often a pure metal) is inserted between the pieces to be joined, and solid-state interdiffusion between the filler metal and the base metal leads to the formation of a low melting point composition (e.g.…”