2019 Physics/Theoretical Colloquium

 

Thursday, August 1 , 2019

3:45 – 4:45 p.m.

MSL Auditorium (TA-3, Bldg. 1698)

 

Refreshments at 3:15pm

 

Speaker: Prof. Ralf Drautz 

Department for Physics and Astronomy of Ruhr-University Bochum, Germany

 

“Atomistic Simulations for Alloy Development”

 

 

Abstract: 

 

 I will show the computational design of a high-temperature shape memory alloy. A design hypothesis was obtained based on insight from tight-binding models and density functional theory calculations of phase stabilities in combination with ab initio molecular dynamics simulations of the martensitic transition. Different alloys were subsequently evaluated with high-throughput density functional theory calculations and the most promising alloys were then fabricated and tested. The computationally predicted alloys shows excellent functional properties at high temperature. 
Next, I will summarise contributions from atomistic simulation for Ni-based superalloys. The chemical and microstructural complexity of the superalloys means that it is not possible to design alloys based on atomistic simulations alone. I will briefly discuss how atomistic simulations can contribute to insight and understanding that may then support alloy development.
Finally, I will use the discussion of the shape memory alloys and Ni-based superalloys to set up a wish list of atomistic simulation capabilities and illustrate some of the challenges involved. Some of our developments, for the prediction of the iron phase diagram and the simulation of phase transformation kinetics, will be highlighted. 

 

 

Bio:

Ralf Drautz is Director of the Department for Atomistic Modelling and Simulation at the Interdisciplinary Centre for Advanced Materials Simulation (ICAMS) and Professor at the Department for Physics and Astronomy of Ruhr-University Bochum, Germany.

 

Ralf carried out his Ph.D. project on ab initio modelling of segregation at Ni-Al surfaces at the Max Planck Institute for Metals Research under the supervision of Manfred Fähnle, in close collaboration with the group of Helmut Dosch and including a one year research stay with Juan M. Sanchez at the University of Texas at Austin.

 

He then moved to Oxford to work with David G. Pettifor on the development of bond-order potentials for semi-conductors and transition metals, initially as a research fellow and later as a senior research fellow and the Materials Modelling Laboratory research fellow.

 

In 2008 Ralf moved to Bochum to set up the Interdisciplinary Centre for Advanced Materials Simulation, a public-private partnership including leading German companies.

 

Ralf’s research focus is on the development of interatomic potentials, including magnetic interatomic potentials, from coarse graining the electronic structure to effective interatomic interactions. The potentials are used in long-time atomistic simulations, for example, for solid-solid or solid-liquid phase transitions. In combination with data-driven and high-throughput methods atomistic simulations are further employed for model validation and materials design.

 

Ralf has authored more than 110 peer-reviewed publications.