Thermokinetic Simulation of Precipitation in NiTi Shape Memory Alloys

International Conference on Innovative Research - ICIR Euroinvent 2017

Cirstea, C.D.^1 ; Karadeniz-Povoden, E.^1 ; Kozeschnik, E.^1 ; Lungu, M.^1 ; Lang, P.^1 ; Balagurov, A.^1 ; Cirstea, V.^1

National Institute for Research and Development in Electrical Engineering ICPE-CA, 313 Splaiul Unirii, Bucharest

030138, Romania^1

关键词: Bulk alloys;    Classical nucleation theory;    Composition changes;    Evolution equations;    NiTi shape memory alloys;    Phase fractions;    Solid state transformations;    Thermokinetics;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/209/1/012057/pdf
DOI  :  10.1088/1757-899X/209/1/012057

来源: IOP

【 摘 要 】

Considering classical nucleation theory and evolution equations for the growth and composition change of precipitates, we simulate the evolution of the precipitates structure in the classical stages of nucleation, growth and coarsening using the solid-state transformation Matcalc software. The formation of Ni3Ti, Ni4Ti3or Ni3Ti2precipitate is the key to hardening phenomenon of the alloys, which depends on the nickel solubility in the bulk alloys. The microstructural evolution of metastable Ni4Ti3and Ni3Ti2precipitates in Ni-rich TiNi alloys is simulated by computational thermokinetics, based on thermodynamic and diffusion databases. The simulated precipitate phase fractions are compared with experimental data.