Microstructure of AgNi and AgSnBi Powders Consolidated by CEC

Abstract

Powder metallurgy is widely used to the production of AgNi and AgSnBi powders employed for electrical contacts. In the work AgNi and AgSnBi powders were consolidated by the cyclic extrusion compression (CEC) method enabling cyclic unlimited deformation. In the initial stage the AgNi powder contained the two phases Ag and Ni, recognized by the EDX technique using scanning electron microscopy (SEM). The investigations shown that the Ni phase is distributed in the form of small granules around larger Ag granules. In the AgSnBi powder phases Ag + Bi + Ag3Sn (ξ) were distributed uniformly. It was found that after the CEC consolidation phases were excellently joined without cavities and cracks. Detailed observations of microstructure have been performed by the transmission electron microscopy (TEM) and revealed inside the consolidated granules nanometric grains with the nanometric twins inside.

Tribological Wear Behaviour of Electrical Contacts Made from AgNi10 Composite

“…Pure silver has, however, too low mechanical properties and is too expensive to be used in its native form. Therefore the requirements of reliable performance of electrical contacts combined with simultaneous reduction of silver consumption pose to manufacturers of contacts new and tough tasks involving the continuous and sustainable improvement of production technology [1,3,4].…”