Role of composition on mechanical properties of refractory multi-element layered ceramics for hypersonic applications.
Abstract
The aim of the proposed research is to develop fundamental understanding of the role of constituent elements on the mechanical properties (such as hardness, plasticity, toughness, wear-resistance) and oxidation resistance of hexagonal-structured multi-element refractory transition-metal alloy carbides (M2C) and determine if the valence electron concentration can be used as a property descriptor for these refractory compounds. M2C films with desired cation compositions, adjustable crystallinity, and possibly variable stoichiometries (C content) will be synthesized using ultra-high vacuum magnetron sputtering. Characterization methods such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS) will be used to determine the film crystallinity, composition, and microstructure, and nanoindentation based techniques will be used to measure hardness, elastic modulus and assess film plasticity-toughness. The onset of oxidation will be determined by XRD measurements at elevated temperatures. This systematic investigation will help in identifying the possible elements and concentrations that will be optimal to enhance the mechanical properties and oxidation resistance in this type of transition-metal carbides. The success in preparing multi-metal M2C layers with controllable cation concentrations will potentially lead to materials with new mechanical-electronic-wear properties and provide new insights into the development of hard- yet-tough materials to be used in high-temperature applications.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 06, 2025
- Source ID
- FA95502510058
Entities
People
- Hanna Kindlund
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- Virginia Tech