Corrosion Resistant Multicomponent Alloys for High Temperature Applications
Abstract
This proposal describes a plan for examining and designing Molybdenum (Mo) based refractorymulticomponent alloys that provide superior structural properties and oxidation resistance at elevated temperatures. These multi-principal element alloys will be computationally engineered for formation solid solution and secondary phases, improved high temperature yield strength and enhanced corrosion resistance, and validated against synthesis and characterization. A hybrid optimization framework is proposed that will concurrently integrate simulation predictions with experimental measurements to propose novel material compositions that achieve the targetedmechanical properties. The Mo-Nb-Ta-V-W refractory HEAs designed and developed through this research program will be directed towards meeting the following technical objectives:a) An atomistically tailored material composition will be obtained that increases the mechanical strength especially at temperatures above 1000oC for application in propulsion systems.b) The resistance of the alloy to ~pesting~ corrosion in oxygen environments will be significantly improved with the incorporation of Si and Mo that induces a higher breakdown potential.c) The construction of a computational-experimental design paradigm will accelerate the pace of discovery of novel HEAs with desired material properties.For the scientific objectives, we will attempt to answer the following questions through this research program: a)What is the threshold elemental composition of Mo in a multi-component alloy for it to assume a high-entropy configuration?b)How can we thermodynamically predict phases of refractory HEAs from the phase diagrams of pairs of elements in the alloy?c)How does the microstructure of Mo-based HEAs under loading vary with changes in temperature and material composition?d)What is the effect of Mo addition on the oxidation resistance and yield strength of the alloy at temperatures approaching melting temperatures of the constituent elements?e)How is corrosion resistance of the alloy affected by presence of varying fractions of Si?f)What is influence of computationally tailoring alloy chemistry on the synthesis of the refractory HEAs?Finally, the educational and technology transfer objectives of the research will be addressed by:a)Development of creative, critically thinking undergraduate and graduate researchers inmechanical engineering and materials science, who will be equipped with the tools to design and examine novel multi-component systems. b)Open-access and liberal dissemination of the computational framework, technology and scientific insights developed through this research to the appropriate audiences through journal publications and seminar presentations, workshops at conferences and to suitable industrial and government parties.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 23, 2016
- Source ID
- N000141612548
Entities
People
- Ganesh Balasubramanian
Organizations
- Iowa State University
- Office of Naval Research
- United States Navy