AG-CERIUM OXIDE ELECTRICAL CONTACT MATERIAL EXCELLENT IN DEPOSITION RESISTANCE AND CONSUMPTION RESISTANCE

摘要

PROBLEM TO BE SOLVED: To obtain an Ag-CeO2 electrical contact material excellent in deposition resistance and consumption resistance by forming a mechanical alloying joining layer on the interface between fine CeO2 grains, dispersedly distributed in a specific proportion in an Ag matrix, and this Ag matrix. SOLUTION: A structure, in which fine CeO2 grains of <=1μm average grain size are dispersedly distributed by 3-15wt.% in an Ag matrix and a mechanical alloying joining layer exists in the interface between the CeO2 grains and the Ag matrix, is formed. This structure can be obtained by mixing Ag powder of <=about 100mesh and CeO2 powder of about 5-10μm average grain size in the prescribed proportion, introducing the resultant powder mixture into an attritor, and performing mixing for the prescribed time to apply mechanical alloying. It is preferable to apply heat treatment to an electrical contact material composed of the resultant composite powder in the air at about 600 deg.C to stabilize the mechanical alloying joining layer.