| 摘要 |
<p>A material and a process for use in making electrical contacts. The material is produced in powder form suitable for later processing into electrical contacts by standard metallurgical techniques generally involving compacting the powdered material to form a compact that preferably has a backing of metallic silver, sintering the compact to form the contact having a fine sintered silver backing and forming or cutting the contact to make it to the desired shape and size. The material, and in most general applications the contact made from the material, essentially consists of silver, approximately 15% cadmium oxide by weight, and lithium carbonate at a proportion of about .005 weight percent of lithium, which is approximately equal to .04 molecular percent of lithium carbonate. The lithium carbonate is added to the powder mixture of silver and cadmium oxide powder mixture as a solution which is thoroughly mixed with the powders to form a slurry to uniformly distribute the lithium carbonate on the surfaces of the powder particles of cadmium oxide and silver by precipitation. The slurry in then dried and precipitated material is pulverized and formed into a compact without reducing the lithium carbonate prior to sintering of the compact. Thus by using lithium carbonate instead of lithium nitrate as known in the prior art, the step of reducing the lithium nitrate to lithium oxide prior to sintering the contact material is eliminated without sacrificing the performance of the contact material. </p> |
