Electrically conductive material and method for making

Abstract

Electrical contact material made from intimate mixtures of silver powder and a powder of a second phase material is shown in which the powder of the second phase material is milled to produce a selected grain distribution of approximately 90% less than 7-10 microns, approximately 50% between 2 and 5 microns and approximately 10% less than 0.8 to 1.0 microns. The powder of the second phase material is added to a silver salt solution, ammonium hydroxide and hydrazine hydrate to form a precipitate of second phase material particles covered with silver. For applications in which the particles need to be free flowing the particles are compacted together without any binder, broken into chunks and milled to provide granules. In one embodiment homogeneously doped tin oxide particles are disclosed in which tin oxide and the oxide of the dopant are dissolved in nitric acid to produce finely dispersed tin oxide and dopant oxide. The oxides are calcined and ground to the selected grain size distribution.

Dependencies are inferred from the claim text.