Title:	First-principles-driven design of novel ductile refractory high-entropy alloys
DNr:	SNIC 2021/5-509
Project Type:	SNIC Medium Compute
Principal Investigator:	Xiaoqing Li <xiaoqli@kth.se>
Affiliation:	Kungliga Tekniska högskolan
Duration:	2021-11-30 – 2022-12-01
Classification:	10304
Homepage:	https://www.kth.se/profile/xiaoqli
Keywords:

Abstract

Refractory high-entropy alloys (RHEAs) represent a new paradigm of high-temperature materials for energy conversion and production applications. RHEAs would hold the promise of increasing the operating temperature by up to 300-500°C compared to Ni-based super alloys, thereby increasing energy efficiency and reducing emissions. However, insufficient room-temperature ductility in most RHEAs developed so far is a major issue. This project addresses this concern, and will accelerate and improve the possibility to identify new ductile RHEAs. My approach is twofold. First, I will investigate intrinsic ductility through physicsbased materials theories, and determine, from first principles, alloying effects on a series of atomicscale parameters that govern intrinsic ductility. I will gain fundamental understanding on how alloy chemistry affects intrinsic ductility, and translate my insights into design strategies to predict new RHEAs with improved intrinsic ductility. Second, I will explore and predict RHEAs with respect to exhibiting the transformation induced plasticity (TRIP) effect. To this end, I will investigate, from first principles, alloying effects on thermodynamic phase stability of RHEAs to access the chemical driving force for the martensitic transformation underlying TRIP. To verify my predictions, my project involves collaboration with experimentalists, whose unique expertise in the characterization of HEAs provides a solid basis to reach my goal.