Improvements in Hollow Article and Method for Making

1,189,697. Making hollow composite metal articles. GENERAL ELECTRIC CO. 18 Aug., 1967 [3 Jan., 1967], No. 38100/67. Heading B3A. [Also in Division C7] Hollow alloy articles are prepared by coating (e.g. by electrolysis or vapour deposition) a core (e.g. of A1 or Mg) with a shell of a higher melting point metal (e.g. Ni, Fe, Co, Cu or Ag) and heating the composite to above the melting point of the core but below that of the shell (e.g. at 1600-2200‹ F.) to cause the core to diffuse into the shell. The core and shell metals are so chosen that the core preferentially diffuses into the shell and the pressure during the diffusion heating is such as not to cause the collapse of the shell. Hollow wire, beads or powders as well as tubes may be made by this method. The core member may be formed as a screen or mesh to form a screen or mesh of hollow members.