Papers by Keyword: Cu-Ag-Cr Alloy

Abstract: By means of a vacuum induction furnace, Cu-Ag-Cr alloy were produced. The wear property and mechanism of Cu-Ag-Cr alloy are studied, and its property was compared with a Cu-Ag alloy. The microstructure of the Cu-Ag-Cr alloy before wear tests was analyzed by transmission electron microscopy. Worn surfaces of the Cu-Ag-Cr alloy were analyzed by scanning electron microscope (SEM) and energy dispersive X-ray spectrum (EDS). Wear tests were conducted under laboratory with a special sliding wear apparatus that simulated the tribological conditions of sliding current collectors on contact wires, and alloy wire was slid against a copper-based powder metallurgy strip under unlubricated conditions. The results show that the wear rate of Cu-Ag-Cr alloy increase with the increase in the sliding speed and the sliding distance. Adhesive wear, abrasive wear and electrical erosion wear are the dominant mechanisms under the electrical current sliding processes. At lower sliding speed, adhesives wear and abrasive wear are the major wear damage, while electrical erosion wear and adhesive wear are the major at higher sliding speed. Under the same conditions, the wear resistance of the Cu-Ag-Cr alloy is 2~3 times of the Cu-Ag alloy.

Abstract: The Cu-Ag-Cr alloy is a kind of aging hardening copper alloy and has excellent combination properties of high strength and good electrical and thermal conductivity. In the present investigation, the aging precipitation behavior of Cu-Ag-Cr alloy is studied, and the effects of aging processes on the microstructure and properties are discussed. Emphasis is on the correlation between the coherency and coarsening behavior of the Cr precipitates. When the alloy aging at low annealing temperatures, the homogeneous dispersed Cr precipitates are observed to be approximately spherical and keep coherent with Cu matrix in the Cu-Ag-Cr alloy, the coherency is lost between at 450°C~520°C, coherency on coarsening process of Cr precipitates at high annealing temperatures, the radium for coherent / semi-coherent transition of the Cr precipitates is determined from TEM micrographs as 15-45nm. Aging in the intermediate stage, coherent and semi-coherent particles can co-exist(15

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