Fabrication of Metal/Oxide Composites via Internal Oxidation and Severe Plastic Deformation
Abstract
Major Goals: The major goal of this project has been to investigate a bulk processing route for producing metal/oxide composite materials via a combination of internal oxidation and equal channel angular pressing (ECAP) of bulk Fe-based alloys. Some important factors that we have identified in creating a material that is a viable candidate for real-world applications are the internal oxidation depth and the post-ECAP microstructure. We have concentrated our efforts on optimizing the alloy compositions, oxidation conditions, and ECAP process variables in order to produce an alloy with maximized internal oxidation depth and a post-ECAP microstructure with ultrafine grains and dispersed oxides. There were two tasks: (1) Obtain the deepest possible internal oxidation - Vary alloy composition, temperature, and oxidizing atmosphere to internally oxidize Fe-Y alloys. These alloys exhibit in-situ internal oxidation. Examine oxidized microstructure and characterize initial oxide size and morphology. (1) Examine microstructure evolution after ECAP - Perform ECAP and study the change in alloy microstructure and distribution of oxides. Measure changes to mechanical behavior after ECAP and after annealing (to assess thermal stability). Assess if ECAP can be used to distribute the oxides through the microstructure. Accomplishments: This work investigated the processing of metal/oxide composites by internal oxidation of a bulk alloy, followed by severe plastic deformation for grain size refinement and oxide dispersion. Internal oxidation rates have been shown to be exceptionally high in alloys exhibiting in situ oxidation. Referred to as a diffusionless or in-situ internal oxidation, this accelerated oxidation process occurs in materials where the reactive solute phase has negligible solubility and diffusivity in the matrix.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 18, 2022
- Accession Number
- AD1196778
Entities
People
- Bryan Webler
Organizations
- Carnegie Mellon University