ELECTROCONDUCTIVE MATERIAL SUPERIOR IN RESISTANCE TO FRETTING CORROSION FOR CONNECTION COMPONENT

摘要

An electroconductive material includes a Cu or Cu alloy base member, a Cu—Sn alloy coating layer, and a Sn coating layer. The Cu—Sn alloy coating layer has a Cu content of 20 to 70 atomic %, and an average thickness of 0.2 to 3.0 μm. The Sn coating layer has an average thickness of 0.2 to 5.0 μm. A surface of the electroconductive material has an arithmetic average roughness Ra of at least 0.15 μm in at least one direction along the surface and 3.0 μm or less in all directions along the surface. The Cu—Sn alloy coating layer is partially exposed at the surface of the electroconductive material. An area ratio of the Cu—Sn alloy coating layer exposed at the surface of the electroconductive material is 3 to 75%. An average crystal grain size on a surface of the Cu—Sn alloy coating layer is less than 2 μm.

主权项

1. An electroconductive material, comprising:
a base member comprising a sheet or strip of copper or copper alloy; a Cu—Sn alloy coating layer; and a Sn coating layer; wherein: at least a portion of the Cu—Sn alloy coating layer is between the base member and the Sn coating layer; the Cu—Sn alloy coating layer has a Cu content of 20 to 70 atomic %; the Cu—Sn alloy coating layer has an average thickness of 0.2 to 3.0 μm; the Sn coating layer has an average thickness of 0.2 to 5.0 μm; a surface of the electroconductive material has an arithmetic average roughness Ra of at least 0.15 μm in at least one direction along the surface; the surface of the electroconductive material has an arithmetic average roughness Ra of 3.0 μm or less in all directions along the surface; the Cu—Sn alloy coating layer is partially exposed at the surface of the electroconductive material; an area ratio of the Cu—Sn alloy coating layer exposed at the surface of the electroconductive material is 3 to 75%; and an average crystal grain size on a surface of the Cu—Sn alloy coating layer is less than 2 μm.