Low-Density, Refractory Multi-Principal Element Alloys of the Cr-Nb-Ti-V-Zr System: Microstructure and Phase Analysis (Postprint)

Abstract

The crystal structure, microstructure, density and Vickers hardness of four multi-principal element alloys, NbTiVZr, NbTiV2Zr, CrNbTiZr, and CrNbTiVZr, are reported. The characteristics of these potential new high-temperature structural alloys are explored. The alloys were prepared by vacuum arc melting followed by hot isostatic pressing (at 1200 deg. C, 207 MPa for 1 h) and homogenization annealing (at 1200 deg. C for 24 h). The alloys have densities of 6.52, 6.34, 6.67 and 6.57 g cm(-3), and Vickers microhardness values of 3.29, 2.99, 4.10 and 4.72 GPa, respectively. The NbTiVZr alloy is essentially a single-phase alloy consisting of a coarse-grained disordered body-centered cubic (bcc) phase with fine, submicron-size precipitates inside the grains. The NbTiV2Zr alloy contains three disordered bcc phases. The CrNbTiZr and CrNbTiVZr alloys contain a disordered bcc phase and an ordered Laves phase. The lattice parameters and compositions of the identified phases are reported. The experimental data are compared with the results of the thermodynamic modeling of non-equilibrium and equilibrium phases in these alloys.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Dec 19, 2012
Accession Number
ADA622790

Entities

People

  • Christopher F. Woodward
  • Daniel Miracle
  • Oleg N. Senkov
  • S. V. Senkova

Organizations

  • Air Force Research Laboratory

Tags

Communities of Interest

  • Space

DTIC Thesaurus Topics

  • Air Force
  • Air Force Research Laboratories
  • Annealing
  • Arc Melting
  • Crystal Structure
  • Crystals
  • Diffraction
  • Electron Microscopes
  • Electron Microscopy
  • Governments
  • Hardness
  • High Temperature
  • Low Density
  • Materials
  • Mechanical Properties
  • Microhardness
  • Microstructure

Fields of Study

  • Materials science
  • Physics

Readers

  • Powder metallurgy of Titanium alloys.