| 摘要 |
1,189,698. Making lightweight metallic structures. GENERAL ELECTRIC CO. 2 Oct., 1967 [3 Jan., 1967], No. 44649/67. Heading B3A. A method of making a lightweight metallic structure 26 includes the steps of coating a core e.g. wires or a mesh, with a shell metal; assembling a plurality of the coated cores to form the structure; and then heating the assembly to a temperature sufficient to diffuse the core metal into the shell metal and to bond the coated cores together but lower than the melting point of the shell metal to produce a lightweight metallic structure consisting of a plurality of hollow shells bonded together. The core metal may be aluminium, magnesium or their alloys and the shell metal may be iron, nickel, cobalt or their alloys, the coated cores being heated to a temperature in the range 1600‹ to 2200‹ F. An example describes the manufacture of a shroud for a gas turbine in which a brazing alloy powder 22 is placed on a backing member 16, nickel wires or mesh 24 are placed on the powder 22 and composite wires 26 are placed on the nickel wires 24. The composite wires 26 consist of aluminium wires coated with nickel, there being 20-27% Al and 73-80% Ni by weight. The stacked base 16 and wires 24, 26 are then placed between holding plates and heated for one hour at about 2000‹ F. in argon to diffuse the aluminium core into the nickel shell and to bond the components together. |
