Session: 03-20-02: Space Manufacturing II

Paper Number: 166710

A Molecular Dynamics Study of Shear Driven Solidification and High Temperature Mechanical Properties of Al₀.₃CoCrFeNi High Entropy Alloy 

High entropy allows exhibits impressive potential for using under extreme condition. This transformative bunch of materials shows high thermal resistance, phase stability and exceptional mechanical strength making them suitable for not only advanced industrial applications but also for advanced manufacturing and aerospace metallurgy. Even though the experimental procedures have showcased different HEA processing techniques, Molecular Dynamics (MD) simulation can still provide a unique aspect on microstructure and deformation behavior from atomic scale mechanisms.

In this study the mechanical properties of Al₀.₃CoCrFeNi HEA solidifying under shear flow condition has been explored to investigate the effect of plastic deformation during the solidification on the mechanical performance, dislocation dynamics and grain refinement at high temperature. Molecular dynamics simulation has been carried out using LAMMPS to model the solidification behavior of Al₀.₃CoCrFeNi. The temperature has been elevated to 2800K first then was cooled down to 298K applying complex shear flow to instigate atomic scale deformation and defect relevant to advanced manufacturing processes of HEA. The other crystal defects and dislocations were observed using Dislocation Extraction Algorithm (DXA) and Common Neighbor Analysis (CAN) of the structure at different temperature. It demonstrated the transition of the structure from fully FCC structure to other types (apart from FCC HCP BCC and ICO) at 2800K.

The result showed that the solidification process with shear flow exhibits better grain refinement, reduced dislocation entanglement and twinning activity resulting in a homogenous and defect resistant microstructure. After solidification at room temperature, uniaxial tensile simulation has been carried out to study the mechanical properties at elevated temperatures. It has been observed that the grain refinement due to shear flow enhances strain hardening with twinning induced plasticity (TWIP) and transformation induced plasticity (TRIP) influencing the low strain and higher strain respectively at high temperature. This led to better yield strength and ultimate tensile strength. These mechanisms interact to allow the alloy to retain both high strength and ductility across a broad temperature range which makes it a potential material for advanced metallurgical engineering, solid-state manufacturing techniques, and high-temperature aerospace uses.

These findings illustrate the role of shear flow in improving the mechanical properties of HEA offering a computational framework to further investigate different advanced manufacturing processes and industrial applications along with sectors where precise control over the microstructure at high temperature is required such as space manufacturing, and high-performance structural applications.

Current research can work as a pathway to bridge the gap between atomistic simulations and real-world processing technologies as well as influence the investigation of other different processing of high-performance alloys.

Presenting Author: Sifat Abdul Bari Islamic University of Technology

Presenting Author Biography: Mr. Sifat Abdul Bari is working as a lecturer in the Mechanical and Production Engineering Department at Islamic University of Technology. He is also pursuing M.Sc. degree in Mechanical Engineering. His research interest lies in the fields of Material Engineering, Molecular Dynamics and Applied Thermodynamics.

Authors:

Sifat Abdul Bari Islamic University of Technology
Chowdhury Sadid Alam Islamic University of Technology
Ashfak Siraj Shuvo Islamic University of Technology
Sakib Al Razi Khan University of North Carolina at Charlotte
M Shafiqur Rahman Louisiana Tech University