Composite brazing material

摘要

A composite brazing metal member comprises an intermediate portion including particles of high temperature melting metal and a brazing metal filling the spaces between the particles and further portions of brazing metal secured to opposite faces of the intermediate portion, the brazing metal melting at a lower temperature than the high melting metal. Powdered high melting metal of 44 micron particle size and powdered brazing metal of 150 micron particle size are blended to form a mixture of the particles with voids therein, the high melting metal being substantially insoluble in the brazing metal at the melting temperature of the brazing metal, the mixture is heated in a mould to a temperature above but preferably not more than 25 DEG F. above the melting point of the brazing metal in hydrogen but below the melting point of the high melting metal and the product is allowed to cool. The product a continuous matrix of brazing metal throughout which is distributed the particles of high melting metal is rolled to plate form with a reduction of at least 50% and additional brazing metal is clad to opposite faces of the plate to form a sandwich. The composite is then rolled or otherwise worked to strip form to produce a composite having an intermediate portion 9 including a continuous matrix 10 of brazing metal with thin plates or laminar particles 11 of the high melting metal distributed therein and two outer portions 12, 13 of brazing metal. The intermediate portion may be produced by sintering a mass of powdered high melting metal and infusing this porous structure with brazing metal. The high melting metal may be nickel and the brazing metal for use therewith may have the following percentage compositions: ..(a).(b).(c).(d) .Ag.84.6.92.5.95.95 .Pd.2.2.7.5..5 .Cu.7.5..4.8. .In.5.5... .Li.0.2..0.2. The high melting metal may be cobalt and the brazing metal may have the following compositions: The high melting metal may be iron and the brazing metal may have the following compositions: Silver or copper may be used with iron. Nickel-iron and nickel-chromium iron alloys may be used as the high melting metal.