High-throughput investigation of diffusion properties in FCC Cu-Ni-Al-(Si, Fe) alloys and application to solidification and homogenization simulations

Abstract

Four groups of Cu-Ni-Al-Si and six groups of Cu-Ni-Al-Fe diffusion couples were prepared, and the concentration distributions within the diffusion layers formed between 1173 K and 1273 K were measured. Using the obtained concentration profiles, the interdiffusion coefficients and mobility descriptions for the face-centered cubic (FCC) Cu-Ni-Al-(Si, Fe) systems were determined through the numerical inverse method in a high-throughput manner. The impact of compositions on the interdiffusion coefficients and relative diffusion rates within the specified composition and temperature ranges was analyzed. Subsequently, the established mobility description was utilized to simulate the solidification and homogenization heat treatment processes in Cu-10Ni-3Al (wt.%), Cu-10Ni-3Al-1Fe (wt.%), and Cu-10Ni-3Al-1Si (wt.%) alloys. The simulated concentration distribution of solutes over the dendrites indicated that Ni and Fe exhibited intra-dendrite segregation, while Al and Si demonstrated inter-dendrite segregation. The inclusion of Fe in Cu-10Ni-3Al alloys slightly increased chemical segregation, whereas the introduction of Si led to the formation of the Ni₂Si phase. The addition of Fe had a minimal impact on the annealing times required to eliminate chemical segregation, while the incorporation of Si reduced the annealing times.