Microstructure evolution of immiscible alloys
during rapid cooling through miscibility gap
during rapid cooling through miscibility gap
(1.School of Materials Science and Engineering,
Harbin Institute of Technology, Harbin 150001, China;
2.Department of Mechanical Engineering, Tsinghua University,
Beijing 100084, China;
3.Institute of Metal Research, The Chinese Academy of Science,
Shenyang 110015, China)
Harbin Institute of Technology, Harbin 150001, China;
2.Department of Mechanical Engineering, Tsinghua University,
Beijing 100084, China;
3.Institute of Metal Research, The Chinese Academy of Science,
Shenyang 110015, China)
Abstract: A numerical model was developed to describe the coarsening of the second phase droplets under the common action of nucleation, diffusional growth and Brownian collision between minority phase droplets during rapidly cooling a hypermonotectic alloy through its miscibility gap. The simulated results show that Brownian mot ion is an important factor influencing the coarsening process. A faster cooling rate leads the supersaturation of the matrix liquid and the nucleation rate to grow up to a higher level, but leads to a smaller droplet radius and a higher number density. This model is used to predict the microstructural evolution of melt-spun Al-30%In ribbon. The model reflects the real physical processes well and is expected to be applicable to other immiscible alloys or other preparing processes.
Key words: immiscible alloy; coarsening of second phase; numerical model