Session: 05-02 Fuel Performance Assessment

Paper Number: 65197

Start Time: August 5, 2021, 04:15 PM

65197 - Atomic Insights on Interaction Mechanism of Dislocation With Void/Impurity/Precipitates in BCC Iron 

Ferritic steels are important cladding and structural material for current and advanced reactors containing Fe as a primary compositional matrix element. Three models containing voids, inclusions such as P and nano oxides embedded in Fe were simulated using LAMMPS code.Interaction and unpinning mechanism of dislocation interations in models were observed and compared by analyzing its stregthening effect through stress stain curve .In considering the interaction of dislocation with voids, it was observed that for all void sizes, dislocation bypass void follow a similar to the orowan mechanism without any loop irrespective of any radii, while for P clusters, dislocation is trapped at the interface and leaves it after making a screw dipole shape and following orowan mechansim. Furthemore, the oxides' dislocation interaction in oxide dispersed in iron follow orowan unpinning mechanism along with loops around oxide. Atomic insights on interaction mechanism between P clusters with dislocation indicate that interaction mechanism is essentially the same for void and P cluster in Fe and their binary alloys i.e. Orowan mechanism whereas for oxide the orowan interaction mechanism along with dislocation around the oxide and it's  direct dependence on the size of the oxide. This work will provide a unique and valuable insight into the strengthening mechanism due to dispersed oxides by providing new parameters for the multi-scale simulation. Our results demonstrate that oxide impedes dislocations and offers hindrance for edge dislocations to saturate further.The values of critical unpinning stress for all models was analyzed and compared. This study provides atomic insight into the onset of plasticity in iron alloys.

Presenting Author: M Mustafa Azeem Xi'an Jiaotong University, Xi'an, Shaanxi, China

Authors:

Muhammad Zubair University of Sharjah
M Mustafa Azeem Xi'an Jiaotong University, Xi'an, Shaanxi, China
Yun Di Xi'an Jiaotong University, Xi'an, Shaanxi, China