Refractory High Entropy Alloys for High Temperature Structural Applications

Abstract

Refractory high entropy alloy (RHEAs) are promising materials for high temperature applications in aerospace and energy sectors. The current proposal involves designing of RHEAs with optimized properties using high throughput calculations, their synthesis using mechanical alloying (MA), understanding their thermal stability, deformation behavior and identifying the thermo-mechanical processing window for forming these RHEAs.In the present proposal, the RHEA compositions will be identified using high throughput calculations. In addition, CALPHAD calculations will be performed to identify the RHEA compositions with brittle to ductile transition temperature below room temperature. The RHEAs will be developed through powder metallurgy route due to their high melting points. RHEA powders will be subjected to high energy ball milling followed by consolidation using spark plasma sintering (SPS) for developing ultrafine grained materials. The microstructural characterization of RHEAs, including high resolution electron microscopy using Titan and local composition analysis at the nano scale by atom probe tomography using local electrode atom probe (LEAP) will be performed. The detailed characterization will lead to better understanding of the mechanism of deformation and fracture in these RHEAs. Deformation studies of RHEAs would be carried out using Gleeble to identify the thermo-mechanical processing window for these new class of alloys.The proposal will establish a strong collaboration between IITM and AFRL and would lead to a long-lasting collaboration in this exciting field between the two countries. In addition, it would also help in developing better understanding in this new and exciting field of RHEAs and could led to new compositions of RHEAs with better properties and could identify their processing windows.

Document Details

Document Type
DoD Grant Award
Publication Date
Jun 11, 2018
Source ID
FA23861814034

Entities

People

  • Srinivasa Budaraju

Organizations

  • Air Force Office of Scientific Research
  • Indian Institute of Technology Madras
  • United States Air Force

Tags

Fields of Study

  • Materials science

Readers

  • Military Engineering.
  • Powder metallurgy of Titanium alloys.

Technology Areas

  • Microelectronics
  • Space