Patent ID: 9028586
Filing Date: 2015-05-12
Classification: C22C,C22F

Abstract:
1. A process for producing cadmium-free materials based on silver, comprising: providing a first alloy comprising silver and at least one oxidizable alloying element, the first alloy being free from cadmium; enlarging the surface area of the first alloy to give a second alloy; performing a first heat treatment of the second alloy to give a third alloy, with the first heat treatment being carried out in a reducing atmosphere; and performing a second heat treatment of the third alloy to give a fourth alloy, with the second heat treatment being carried out in an oxygen-containing atmosphere, wherein the second heat treatment is an internal oxidation step which is carried out in two temperature stages, where the first stage is carried out at a first temperature of from 500° C. to 150° C. below the solidus temperature of the first alloy for a first period of time and the second stage is carried out at a temperature of from 500° C. to 5° C. below the solidus temperature of the first alloy for a second period of time, with the second temperature being 70-160° C. higher than the first temperature, and wherein the second heat treatment is carried out in an oxygen-containing atmosphere comprising elemental oxygen, nascent oxygen, ozone, or mixtures thereof at ambient pressure.