Comparative studies of different solutes effects on microstructure and comprehensive performance of coherent precipitation-strengthened Cu–Ni–Al alloys

Abstract

Multi-componentization can further improve the heating resistance of Cu–Ni–Al alloys, enabling them to withstand more demanding situations. Unfortunately, the limited researches have been done on the wear and corrosion resistance of the heat-resistant Cu–Ni–Al alloys, resulting in the lack of relevant evidence in the practical application. In this work, a comparative study of differential types of trace element, Si (the stronger enthalpy interaction element), Sn (the weaker enthalpy interaction element) Cr or Zr (grain boundary strengthening element), effects on microstructure, wear and corrosion resistance will be done, Furthermore, the effect of different trace elements on the surface electron work function and electrochemical behavior of Cu–Ni–Al alloys is reflected by SPM surface potential model. The results indicate that the precipitation of dual nano-phase and accelerated precipitation of γ′ phase can be realized through the addition of Si, Sn, Cr and Zr, in which the value of δγ-γ′ increase sharply after adding Si and it is not conducive to the preservation of cuboidal γ′ phase. The addition of Si, Cr and Zr can improve electron work function distribution and mechanical property, wear, and corrosion resistance of the alloys, in which Si is more conducive to the improvement of wear resistance and mechanical properties of the alloy, while the alloy with Cr and Zr shows the excellent corrosion resistance. The addition of Sn will weaken the enthalpy interaction of the alloy system, reduce the electron work function of the alloy, and have adverse effects on the wear and corrosion resistance of the alloy.