Roll bonding

Schematic drawing of the roll bonding process

Roll bonding is a solid state, cold welding process, obtained through flat rolling of sheet metals. In roll bonding, two or more layers of different metals are passed through a pair of flat rollers under sufficient pressure to bond the layers. The pressure is high enough to deform the metals and reduce the combined thickness of the clad material. The mating surfaces must be previously prepared (scracthed, cleaned, degreased) in order to increase their friction coefficient and remove any oxide layers. The process can be performed at room temperature^[1] or at warm conditions. Heat may be applied in order to improve the ductility of metals and improve the strength of the weld.

Applications

The applications of roll bonding can be used for cladding of metal sheets, or as a sub-step of the accumulative roll bonding. Bonding of the sheets can be controlled by painting a pattern on one sheet; only the bare metal surfaces bond, and the un-bonded portion can be inflated if the sheet is heated and the coating vaporizes. This is used to make heat exchangers for refrigeration equipment. ^[2]

References