The invention discloses a method for preparing a
bimetal composite plate by stirring friction braze
welding. The method comprises that: a plate with small
hardness is used as a covering layer
metal plate; a plate with high
hardness is used as a base layer
metal plate; the covering layer
metal plate and the base layer metal plate are horizontally fixed on a working platform surface in a
lap joint mode; solders which can generate eutectic reaction with one of the upper / base layer metal plates are preset between the upper / base layer metal plates; a non-
needle type cylinder friction device is arranged over the covering layer metal plate; the non-
needle type cylindrical friction device is made to rotate and be pressed to be closely contacted with the
surface layer of the covering layer metal plate, but not penetrate the covering layer metal plate, and the non-
needle type cylindrical friction device rotates in the original position or moves forward along the surface of the covering layer metal plate while rotating; by utilizing frictional heat to melt the solders, the upper / base layer metal plates are both quickly melted in the solders, thereby achieving excellent interface combination; and the excessive solders are squeezed out, and a thin and dense
soldering seam is formed, so that the
bimetal composite plate is prepared. Compared with the braze
welding in a furnace, the method has the advantages of high efficiency,
energy conservation, pressure lead-in, unnecessary
soldering flux and
gas protection and short
holding time at a high temperature.