Identifying Short-Range Ordering on Multi-Principal Element Alloys and their Effect on Mechanical Properties and Corrosion Resistance

Abstract

Executive Summary/Abstract: Multi-Principal Element Alloys (MPEAs) are novel materials with flexible composition and properties. Despite the commercial appeal of some compositions, the study of MPEAs has been a pathway to deepen our understanding in several physical metallurgy principles, especially regarding the multitude of ways that different solutes can interact to control several alloy properties. On the core of this discussion, the presence and effect of preferable atomic configurations, namely Short-Range Ordering (SRO), over completely random states is being widely debated over the past few years. Currently, even for the most studied alloys, it is unclear under which processing circumstances SRO forms, and how relevant it is for the materials properties. In the present project, the formation and impact SRO in multiple properties will be systematically investigated in the equiatomic Cr33Co33Ni33 and Fe25Cr25Co25Ni25 MPEAs. To induce SRO, long heat treatments at relatively low temperatures will be performed. The alloys will be characterized in depth by a combination of multiple direct and indirect measurement techniques. Samples with and without SRO will be mechanically tested under different temperatures and strain rates, the corrosion behavior via polarization curves will also be evaluated. In-situ deformation experiments as well as localized deformation techniques will be employed to evaluate the effect SRO have on local and global mechanical behavior. The two main goals of the current project are to, first, evaluate and compare the available characterization techniques to identify SRO and, second, to understand if SRO can indeed significantly change key mechanical properties and corrosion behavior of these widely studied MPEAs in a variety of mild and more extreme conditions. The results will be key to identify how promising SRO is for the field of FCC MPEAs in tuning the properties of these alloys.

Document Details

Document Type
DoD Grant Award
Publication Date
Sep 01, 2023
Source ID
W911NF2310310

Entities

People

  • Francisco Gil Coury

Organizations

  • Army Contracting Command
  • United States Air Force

Tags

Fields of Study

  • Materials science

Readers

  • Powder metallurgy of Titanium alloys.
  • Surface Engineering/Surface Coating Technology.
  • Theoretical Analysis.