High temperature corrosion of nanocrystalline three-phase Cu-20Ag-20Cr bulk alloy

摘要

High temperature corrosion of nanocrystalline MACu-20Ag-20Cr(at.%) alloy prepared by mechanical alloying(MA) was studied as compared with that of coarse grained PMCu-20Ag-20Cr alloy prepared by powder metallurgy(PM). PMCu-20Ag-20Cr alloy forms an external layer composed of CuO or CuO and CuCr2O4, while the internal layer is composed of alloys as well as Cu, Ag and Cr oxides. MACu-20Ag-20Cr alloy forms the same scale structures as PMCu-20Ag-20Cr alloy at 600 degrees C. On the contrary, it forms a bright layer of Ag2O at 700 degrees C, but an irregular and continuous layer of chromia at 800 degrees C, which prevent the alloy from being oxidized further. (C) 2016 Elsevier Ltd. All rights reserved.