| 摘要 |
<p>A method of producing a metal coating or object comprises flame-spraying simultaneously on to a surface a plurality of metals having melting-points which differ by at least 150 DEG F., the lowest melting-point metal being a self-fluxing brazing alloy, and subsequently sintering the deposit at a temperature at or above the melting-point of the self-fluxing brazing alloy but below the lowest melting-point of the other metals. A mould may be made by coating a plaster model with alkali metal silicate; flame-spraying a layer of high-melting metal, e.g. an alloy consisting of Cr 15%, Si 4.5%, Fe 4%, B 3.95%, Ni balance, on to the silicate coating; flame-spraying simultaneously on to the high-melting metal a plurality of metals of which one is a self-fluxing brazing alloy; removing the model; and finally sintering the mould in charcoal. The mould may be reinforced by surrounding it with a body of cast aluminium. The self-fluxing brazing alloy may contain P, Sn, Cd, Li or B as deoxidizer. The following combinations of metals are referred to (1) copper, chrome-copper or phosphorbronze consisting of Cu 94.75%, Sn 5% and P 0.25% with a self fluxing silver brazing alloy consisting of Cu 80%, Ag 15% and P 5%; (2) ferrous metal, nickel or nickel alloy, with a self-fluxing brazing alloy consisting of Ni 0.5-3%, Li 0.5-2%, Ag remainder, or Ni 0.5-20%, B 0.5-2%, Li 2-15%, Cu remainder and (3) beryllium-copper with a self-fluxing brazing alloy containing lithium. The plurality of metals is preferably sprayed together from the same flame-gun.</p> |
