Ternary Diffusion and Thermodynamic Interactions in α Cu–Ni–Sn Solid Solutions

Abstract

have been performed in a temperature range from 1023 to 1123K. The concentration profiles indicate that the diffusion rate of Sn is greater than that of Ni in these solid solutions. The influence of the indirect flux becomes larger with increasing Ni concentration. The interdiffusion fluxes evaluated from the equations of Dayananda and Kim show that the zero-flux planes exist in the diffusion zone of Cu-Ni-Sn couples. The diffusion paths show S-shaped curves. The direct coefficients DCuSnSn and DCuNiNi are positive, and the indirect coefficients DCuSnNi and DCuNiSn are negative. The four interdiffusion coefficients are very sensitive to the Ni and Sn concentrations. The temperature dependence of DCuSnSn,DCuSnNi,DCuNiNi and DCuNiSn at the composition of Cu-6.0 at%Ni-3.7 at%Sn can be expressed by the following equations:and The estimated values of interaction parameters indicate that the interaction energy of the Ni-Sn bond is much larger than those of the Cu-Sn and Cu-Ni bonds.

The Effect of Deformation on Microstructure of Cu-Ni-Sn Aging Alloys

“…Nowadays, copper-nikel-tin spinodal alloys are high perfomance material that can stably operate under combination of severe load and high speed in bearing application in aircraft, in heavy duty mechanical systems wich reqiueres additionl corrosion resistance [1]… In the tenary alloys that include Cu-9Ni-6Sn, Cu-15Ni-8Sn, the mechanical properties can be controlled by heat treatment [2,3,4]. The tenary alloys are homogenized above the miscibility gap to develop a uniform solid solution of a single phase (phase α), followed by rapid quenching to room temperture to retaint homogenized solution state, then alloy was aged at temperture within the spinodal region.…”