KY EPSCoR: FY21: Department of Energy EPSCoR State Match: Discovery, Design, Synthesis and Testing of High Performance Structural Alloys

Grants and Contracts Details

Description

Summary: The research objective of the proposed 3-year study is to establish a foundational metallurgical understanding of the composition-structure-property relationships governing advanced structural alloys, including multi-principal element alloys (MPEAs), which are also known as high-entropy alloys. Existing metallurgical knowledge is not sufficient to reliably design, develop or process MPEAs. To address this, the proposing team will take a multidisciplinary and multi-scale approach that integrates experiment and computation to screen MPEA systems, and build a comprehensive understanding of phase formation & stability, alloy structure and elemental distribution, and the defects and mechanisms that govern mechanical behavior. The combined experimental-computational research effort will yield sufficient knowledge to identify, predict and design novel application-relevant structural alloys. Motivation: Contemporary metallurgy enables the design, selection and processing of a wide range of alloys for technological needs. Continued enhancement of conventional alloy properties, though, is increasingly challenging and will likely yield only incremental improvements. In contrast, the largely unexplored phase space of MPEAs offers the potential for transformative enhancement of metallic material properties. MPEAs based on 3d transition metals have already been identified and shown, in some cases, to exhibit better properties than conventional steels/alloys, and along with their intermediate densities between steels and Ti alloys, offer new options for materials design. Harnessing MPEAs requires a full metallurgical understanding of MPEA systems and reinterpretation of many conventional metallurgical concepts in the context of compositionally complex alloys. Scope of Capabilities: The broad experimental and computational skills of the proposing team encompass a spectrum of methodologies from high-throughput to effort-intensive capabilities, and which address structure-property relationships across multiple length scales. In describing the team’s capabilities, we utilize the taxonomy developed in recent years by Miracle et al. that captures the balance between high-throughput and high-fidelity investigations of MPEAs. • Stage 0: Screening of MPEA Composition Space for Candidate Alloys and Structures o Experiment – Combinatorial synthesis of MPEA materials with 2D gradients in composition and structure; high-speed nanoindentation mapping; environmental testing for oxidation and corrosion resistance (Balk at UK, Minor at LBNL) o Computation – High-throughput predictive calculations and first-principles database parameterization (Chrzan and Asta at LBNL) • Stage 1: Prediction and Characterization of Mechanical Properties o Experiment – Fabrication of bulk samples with single- and gradient-composition/structure; arc melting and small-scale mechanical testing; comprehensive nanoindentation studies; heat treatment for microstructure and phase evolution (Balk at UK, Minor at LBNL) o Computation – Phase field and molecular dynamics calculations of deformation, as well as phase transformations; multi-scale mechanics (Chrzan and Asta at LBNL) • Stage 2: Understanding Defects and Mechanisms o Experiment – Casting and growth of samples for full-scale mechanical testing of downselected selected MPEAs; high-temperature testing; advanced and in-situ characterization of deformation microstructure, including dislocation cores (Balk at UK, Minor at LBNL) o Computation – First-principles and molecular dynamics calculations of atom-resolved lattice structure/properties; atomic-scale order/disorder; structure and kinetics of defects; parameterization of multi-scale models for mechanical behavior (Chrzan and Asta at LBNL) Experimental Efforts: Thin film samples with 2D composition gradients will be fabricated using combinatorial deposition and annealing. These samples will be used to screen MPEA systems
StatusFinished
Effective start/end date7/1/206/30/23

Funding

  • KY Economic Development Cab

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