Abstract
We investigated the kinetics of martensitic transformation (MT) using a Ni45Co5Mn36.5In13.5 alloy. The MT start temperature Ms of this alloy decreases gradually with increasing applied magnetic field up to 1.5T, and Ms vanishes under 2T. Under this magnetic field, the MT shows a clear C-curve in the time–temperature transformation (TTT) diagram. To understand this behavior, we evaluated the difference in the free energy Δg of the parent phase and the martensite phase by measuring the specific heat of the alloy. We found that Ms largely deviates from the equilibrium temperature T0 as the magnetic field increases. We also found that Δg at Ms increases as Ms decreases. Using Δg thus evaluated and a thermal activation model for the nucleation of martensite, we calculated the TTT diagram for various magnetic field strengths so as to reproduce the experimentally obtained one. We estimated the size of the thermally activated cluster, which may be regarded as the nuclei of martensite, to be (5nm)3.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
