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Indexed by:Journal Papers

Date of Publication:2019-10-15

Journal:JOURNAL OF ALLOYS AND COMPOUNDS

Included Journals:SCIE

Volume:805

Page Number:404-414

ISSN No.:0925-8388

Key Words:Copper alloy; Microstructure; Resistivity; Heat resistance

Abstract:The heat resistance of copper alloys is desirable to improve while it services at high temperature as electrically and thermally conductive components. In present paper, the strengthening pattern of nickel-based superalloys is expected to be applied in copper alloys. Here the Cu50Ni37.5M12.5 (M = Al, Cr, Mo) alloys were prepared by vacuum arc melting and heat-treated in the corresponding conditions to obtain three different kinds of typical microstructure. The room temperature (RT) properties (hardness and resistivity) and high temperature properties (melting point, softening temperature and variable temperature resistivity) of the three alloys are contrasted and analyzed in detail. The Cu50Ni37.5Al12.5 alloy strengthened through the gamma' phase coherent precipitation shows the best conductivity and highest hardness (5.47 % IACS (International Annealed Copper Standard) and 310.1 HV). The splitting of the gamma' phase is contributing to hardening at high aging temperature. The resistivity-temperature behavior of the three alloys shows that the resistivity with rising temperature consists of the ideal lattice resistivity and the resistivity increment due to the defects. The Cu50Ni37.5Al12.5 alloy has the smallest room temperature resistivity and its resistivity maintains the lowest during the whole heating process (RT-1077K). Therefore, the coherent precipitated gamma' phase is expected to improve the heat resistance of the copper alloys while maintaining its electrical conductivity. (C) 2019 Elsevier B.V. All rights reserved.