Simulation of bcc-Cu precipitation in ternary Fe-Cu-M alloys

• Published in: Computational materials science Vol. 141; pp. 101 - 113
• Main Authors: Guo, H., Enomoto, M., Shang, C.J.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.2018
• Subjects: Alloy element; Cu precipitation; Gibbs-Thomson effect; Growth; Interfacial tie-line; Nucleation; Gibbs-Thomson effect; Nucleation; Alloy element; Cu precipitation; Growth; Interfacial tie-line
• ISSN: 0927-0256; 1879-0801
• DOI: 10.1016/j.commatsci.2017.09.023

[Display omitted] •The influence of alloy element diffusion on the growth of Cu particles is small.•Al increases the number and decreases the mean radius of Cu particles.•Mn has opposite effects to Al due to increase in Cu solubility in ferrite.•The effect of Ni on the particle number could be less pronounced in a ternary alloy.•The capillarity has a significant influence on the composition of Cu particle. The precipitation of bcc-Cu in the ferrite matrix of Fe-Cu-M alloys, where M is Al, Mn and Ni, is simulated using the Kampmann-Wagner-Numerical (KWN) model with the classical nucleation theory (CNT) and the theory of diffusion-controlled growth by Zener and Kirkaldy. The instantaneous local equilibrium interfacial concentrations of Cu and M were calculated at every time interval, which revealed that the influence of M diffusion is insignificantly small no matter it is faster or slower than the diffusion of Cu. Whilst the capillarity-corrected Cu concentration at the interface in the matrix essentially dictated the growth and coarsening, the concentration of M in the particle affected by capillarity also had an appreciable influence on the number of Cu particles. Al decreased the Cu solubility in the bcc-Fe matrix, increased the number of Cu particles, and decreased the matrix supersaturation fastest. Mn decreased the number and increased the mean radius of bcc-Cu particles due to the increase in Cu solubility to a large extent. The effects of Ni on particle number were less pronounced than one would expect from experimental observations in multicomponent steel. The small changes in particle/matrix interfacial energy and strain energy of nucleus can alter significantly the evolution of particle number and size during aging.