Interaction mechanism of elements and second phase characteristics in as-cast Cu–15Ni–8Sn–(1Al–0.1Y) alloy

Abstract

In this article, the effects of Al and Y elements on the microstructure and mechanical properties of Cu–15Ni–8Sn alloy were studied. The interaction mechanism between elements is proved by first-principles calculation. The results show that the strength of Cu–15Ni–8Sn–1Al–0.1Y alloy reaches 760 MPa, and the hardness of matrix (α-Cu) and Sn-rich phase (γ) are 292.43 and 341.65 HV, respectively, which are 23.78%, 97.80% and 65.21% higher than those of Cu–15Ni–8Sn alloy, respectively. The formation of a large number of dispersed nano-scale Ni3Al second phase is the main reason for the great improvement of the strength of the alloy. In addition, the solid solution of Al and the formation of the Ni17Y2 phase improve the hardness of the Sn-rich phase.