high entropy alloys

"Order Parameter Engineering for Random Systems" published in High Entropy Alloys and Materials

Abstract:

Two postdoctoral positions are available in the Department of Mechanical Engineering at the University of British Columbia (UBC), Vancouver Campus. The positions are described below and involve the use of large-scale ab-initio simulations in combination with machine learning models to accelerate materials discovery. The positions are funded for two-years and available in the modelling and simulation group, lead by Prof. Mauricio Ponga.

https://doi.org/10.1088/1361-651X/ab3b62

Abstract

We are soliciting applications from outstanding candidates for a postdoctoral research position in the Computational & Experimental Materials Engineering Laboratory, at the Department of Mechanical Engineering, Johns Hopkins University starting immediately.

The position is available immediately and applications will be reviewed until position is filled. This will be a one year position renewable depending on performance.

Effects of Cu, Mn, Al, Ti, Mo on generalized stacking fault energies, Rice-criterion ductilities, and twinabilities of CoCrFeNi-based face-centered cubic high entropy alloys were investigated using density functional theory calculations. The calculated barrier energies and twinnabilities revealed that the addition of Ti or Mo increased the tendency of dislocation glide and deformation twinning, while addition of Mn, Cu and relatively high amount of Al facilitated dislocation gliding and martensitic transformation. Low amount of Al resulted in only dislocation gliding.

Selection and thermal stability of phases are important in design of high entropy alloys (HEA). In this study, phase formations in cast AlFeCoNiCu HEA were investigated. Ab-initio molecular dynamics (AIMD) simulations were used to determine crystal structures of phases at different temperatures in equiatomic composition of AlFeCoNiCu. The AIMD results showed a possible coexistence of a face-centered cubic (fcc) phase and a bodycentered cubic (bcc) phase at the room temperature and indicated stabilization of a single fcc phase above 1070 K at the equiatomic composition of AlFeCoNiCu.

We are looking for a highly motivated PhD candidate for a project related to the development of cracking computational models in high entropy alloys.

Context

In the frame of a collaborative project between three universities (Ulg, UCL and ULB), the main objective of the offered PhD position will be to develop a numerical modeling framework for cracking in high entropy alloys, known for their high toughness properties.

PhD opportunity