Bonding a highly conductive arc-resistant electrical contact pad on a metal body

A method of joining a highly conductive arc-resistant electrical contact pad of thin sheet form to a predetermined portion of a surface of a metal body, comprising the steps of:

• (a) providing a contact pad of silver and of thin sheet form having a thickness of 0.0005 to 0.010 inches,
• (b) providing a metal body to which said contact pad is to be joined,
• (c) providing between said contact pad and said predetermined surface portion of said body an intermediate layer having opposed surfaces that respectively contact said pad and said surface portion, each of said opposed surfaces being of a metal that:
• (i) has a melting point of about 450.degree. F. and lower than that of the metal of the surface it contacts and (ii) is compatible with the metal of the surface it contacts;
• (d) placing the combination of said contact pad, said intermediate layer, and said metal body between a pair of opposed electrodes that contact said pad and said body and applying pressure through said electrodes that forces said contact pad toward said metal body with said intermediate layer located between said pad and said body,
• (e) passing current between said electrodes while said pressure is being applied, thereby heating said pad, said layer, and said body,
• (f) discontinuing said current for a brief cooling interval and then repeatedly passing current between said electrodes until the metal of said opposed surfaces of said intermediate layer has been sufficiently heated to melt,
• (g) discontinuing said heating and allowing the molten metal of said intermediate layer to solidify, thereby providing a metallurgical bond between said pad and said body.