2021 Volume 60 Issue 1 Pages 41-44
The effects of amount of solute atoms on the formation of heterogeneous–nano structure in Cu–Ni–Si system alloys was investigated using Cu–2.01mass%Ni–0.44mass%Si, Cu–3.03mass%Ni–0.65mass%Si, Cu–3.60mass%Ni–0.77mass%Si, and Cu–4.2mass%Ni–0.91mass%Si alloys. All the alloys were subjected to solution–treatment and subsequent cold–rolling up to a reduction of 90% in thickness. In each alloy, conventional lamellae parallel to the rolling direction were formed after cold rolling. As the Ni and Si contents increased, in addition to the lamellae, shear bands with an angle to the rolling direction and deformation twin domains surrounded by the shear bands were formed, eventually leading to the development of distinct heterogeneous–nano structure. The Cu–4.2mass%Ni–0.91mass%Si alloy after the cold rolling was aged at 450°C for 5 min, and an excellent tensile strength of 964 MPa was achieved.
