Method of bonding amalgam inserts in cavities and structure thereby produced

摘要

In a process of bonding an amalgam insert in a cavity in a metal body the cavity is filled with an immersion type metal plating solution containing a soluble precious metal compound and a buffering ammonium compound so that a precious metal coating is formed on the cavity wall, the solution is then removed and the coated cavity is filled with an amalgam of finely divided metal which sets and the mercury combines with the precious metal coating. The precious metals specified are Au, Ag, Pt and Pd and the soluble compounds are potassium gold cyanide, potassium silver cyanide, silver acetate and platinum and palladium diamino nitrites. Examples of buffering agents are ammonium hydroxide and ammonium citrate and chelating agents such as urea, E.D.T.A., cyanoacetamide, dicyandiamide, sulphosalicylic acid and ethylmediamine may also be used in the solution. The amalgams specified are those of Ag, Au, Pd, Pt, Rh, Sn and Bi and the metal body may be of Ni, Cd, Zn, Al and alloys, steel, tungsten, solder, pewter or "Alumel" (Trade Mark). As shown in the Figure a cavity 2 or 3 is first coated and the amalgam 7 is packed into the cavity and allowed to set. In a specific application a thermocouple 8 is placed in the coated cavity and the amalgam packed around. Specification 872,785 and U.S.A. Specification 1,963,085 are referred to.