Abstract Means and method for rendering solderable a stainless steel body resistant to corrosive attack from common electrolytes. The method includes the steps of covering at least one surface of a stainless steel body with layers of metal including a first metal layer selected from the group consisting of nickel, cobalt and chromium which serves as a barrier layer to the diffusion of a subsequent metal layer or layers therethrough to the stainless steel body. The subsequent metal layer is resistant to corrosive attack from common electrolytes and is solderable. The subsequent metal layer consists of silver alloyed with a noble metal selected from the group consisting of gold, palladium, platinum, rhenium and osmium. The alloy layer may be formed by covering the barrier layer with a layer of silver and then a layer of gold or one of the other metals. The layered stainless steel body is heated to a temperature below the melting point temperature of the metal layer having the lowest melting point so that the layers, with the exception of the barrier layer, diffuse into one another, thereby forming the alloy layer overlaying the barrier layer which is resistant to corrosive attack from common electrolytes and is solderable. The stainless steel body is rendered solderable.
A solderable part as claimed in claim 1, wherein said first layer is a metal selected from the group consisting of nickel, chromium and cobalt and said second layer is an alloy wherein one of the constituents thereof is selected from the group consisting of silver and copper and the other constituents of said alloy is selected from the noble metal group consisting of gold, palladium, platinum, rhenium and osmium.
Claim 2
Dependent Claim
54 words
A solderable metal part as claimed in claim 2, wherein said first layer is about 0.0002 to 0.0004 inches thick and said alloy layer consisting essentially of said noble metal having an original thIckness of about 0.00005 to 0.0002 inches and said first constituent having an original thickness of about 0.00008 to 0.002 inches.
Claim 3
Dependent Claim
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A solderable metal part as claimed in claim 3, wherein the thickness of said alloy layer is about 1-16 percent greater than the total thickness of the layered constituents.
Claim 4
Dependent Claim
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A solderable metal part as claimed in claim 2, wherein said alloy constituents are silver and gold.
Claim 5
Dependent Claim
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A solderable metal part as claimed in claim 5, wherein said silver-gold alloy consists essentially of about 80-98 percent by weight silver, the remainder essentially gold.
Claim 6
Dependent Claim
27 words
A solderable metal part as claimed in claim 6, wherein said silver content of said alloy is about 88 percent by weight, the remainder essentially said gold.