Evolution of Microstructure in the BCC-HCP Martensitic Phase Transition in Zirconium

1997 ◽  
Vol 492 ◽  
Author(s):  
G. J. Ackland ◽  
U. Pinsook

ABSTRACTWe report molecular dynamics simulations of the martensitic phase transition from bcc to hep in zirconium. We show the evolution of a laminated twinned microstructure, in which some plastic deformation has occurred to rotate the twins manifested as basal stacking faults. This rotation is such as to alter the twinning angle from the 60° between the hep variants to the 61.5° angle of the low energy (1011) twins. These are thus identified as a cause of microscopic irreversibility in the transition.

CrystEngComm ◽  
2021 ◽  
Author(s):  
Andrey Sarikov ◽  
Anna Marzegalli ◽  
Luca Barbisan ◽  
Massimo Zimbone ◽  
Corrado Bongiorno ◽  
...  

In this work, annihilation mechanism of stacking faults (SFs) in epitaxial 3C-SiC layers grown on Si(001) substrates is studied by molecular dynamics (MD) simulations. The evolution of SFs located in...


Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3631 ◽  
Author(s):  
Binjun Wang ◽  
Yunqiang Jiang ◽  
Chun Xu

Using molecular dynamics (MD) simulation, the austenitic and martensitic phase transitions in pure iron (Fe) thin films containing coherent twin boundaries (TBs) have been studied. Twelve thin films with various crystalline structures, thicknesses and TB fractions were investigated to study the roles of the free surface and TB in the phase transition. In the austenitic phase transition, the new phase nucleates mainly at the (112)bcc TB in the thicker films. The (111¯)bcc free surface only attends to the nucleation, when the film is extremely thin. The austenitic transition temperature shows weak dependence on the film thickness in thicker films, while an obvious transition temperature decrease is found in a thinner film. TB fraction has only slight influence on the austenitic temperature. In the martensitic phase transition, both the (1¯10)fcc free surface and (111)fcc TB attribute to the new body-center-cubic (bcc) phase nucleation. The martensitic transition temperature increases with decreased film thickness and TB fraction does not influent the transition temperature. In addition, the transition pathways were analyzed. The austenitic transition obeys the Burgers pathway while both the Kurdjumov–Sachs (K–S) and Nishiyama–Wassermann (N–W) relationship are observed in the martensitic phase transition. This work may help to understand the mechanism of phase transition in the Fe nanoscaled system containing a pre-existing defect.


2012 ◽  
Vol 61 (3) ◽  
pp. 030701
Author(s):  
Song Qing ◽  
Ji Li ◽  
Quan Wei-Long ◽  
Zhang Lei ◽  
Tian Miao ◽  
...  

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