Molecular Dynamics as a Means to Investigate Grain Size and Strain Rate Effect on Plastic Deformation of 316 L Nanocrystalline Stainless-Steel

In the present study, molecular dynamics simulations were employed to investigate the effect of strain rate on the plastic deformation mechanism of nanocrystalline 316 L stainless-steel, wherein there was an average grain of 2.5-11.5 nm at room temperature. The results showed that the critical grain size was 7.7 nm. Below critical grain size, grain boundary activation was dominant (i.e., grain boundary sliding and grain rotation). Above critical grain size, dislocation activities were dominant. There was a slight effect that occurred during the plastic deformation mechanism transition from dislocation-based plasticity to grain boundaries, as a result of the stress rate on larger grain sizes. There was also a greater sensitive on the strain rate for smaller grain sizes than the larger grain sizes. We chose samples of 316 L nanocrystalline stainless-steel with mean grain sizes of 2.5, 4.1, and 9.9 nm. The values of strain rate sensitivity were 0.19, 0.22, and 0.14, respectively. These values indicated that small grain sizes in the plastic deformation mechanism, such as grain boundary sliding and grain boundary rotation, were sensitive to strain rates bigger than those of the larger grain sizes. We found that the stacking fault was formed by partial dislocation in all samples. These stacking faults were obstacles to partial dislocation emission in more sensitive stress rates. Additionally, the results showed that mechanical properties such as yield stress and flow stress increased by increasing the strain rate.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:13

Enthalten in:

Materials (Basel, Switzerland) - 13(2020), 14 vom: 20. Juli

Sprache:

Englisch

Beteiligte Personen:

Husain, Abdelrahim [VerfasserIn]
La, Peiqing [VerfasserIn]
Hongzheng, Yue [VerfasserIn]
Jie, Sheng [VerfasserIn]

Links:

Volltext

Themen:

316 L austenitic stainless-steel
Embedded atom method (EAM)
Grain size
Journal Article
Molecular dynamics
Plastic deformation mechanisms
Strain rate

Anmerkungen:

Date Revised 29.03.2024

published: Electronic

Citation Status PubMed-not-MEDLINE

doi:

10.3390/ma13143223

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM312745044