High density sintered prods. made from silver powders - esp. electric contacts, are subjected to multistep sintering at progressively increasing temps. to obtain high density

摘要

The powder consists mainly or entirely of silver, and is pressed into a green blank which is sintered in nitrogen in at least two successive steps with increasing temps. In each step, sintering occurs at a specific temp. for a specific time. The result is that prods. with a density of min. 90% of the theoretical density are obtd., because shrinkage occurs during the final sintering stage. The initial powders are esp. those employed in mfg. sintered electric contacts, e.g. Ag; Ag-CdO;, Ag-Ni; or Ag-carbon.