PURPOSE: To prevent a defective pressure welding by heating the Al plate containing a pressure welding element in vacuum in performing the pressure welding of the Al plates in plural sheets including the Al plate containing the pressure welding inhibiting elements of Mg and Zn.
CONSTITUTION: A clad plate is manufactured by press-welding the Al plate in≥two sheets including at least one sheet of Al plate (Al alloy plate inclusive) containing the pressure welding inhibiting element of Mg and/or Zn. In this case, the press-welding inhibiting element of the surface part of the joining face to the other Al plate in this Al plate is evaporated by heating in vacuum the Al plate containing said pressure welding inhibiting element. All of Al plates are thereafter press-welded with their overlapping. With this method no pressure welding inhibiting element exists on the surface part of the Al plate to be press-welded and a good pressure welding is performed. And yet in evaporating the pressure welding inhibiting element the oxide film formed on the Al plate surface is broken by said element, numerous unevennesses are caused on the Al plate surface and the pressure weld ability is further improved.
TAKASAKI KANJI
KONDO MIKIO
