Researcher(s)
- Matt LeCates, Mechanical Engineering, University of Delaware
- Xavier Stevenson, Mechanical Engineering, University of Delaware
Faculty Mentor(s)
- Zubaer Hossain, Mechanical Engineering, University of Delaware
Abstract
Ultra-high temperature ceramics (UHTCs) have been a topic of great interest for researchers over the past half-century due to their desirable mechanical and thermal properties. Consisting of transition metal carbides, borides, and nitrides, UHTCs benefit from strong covalent bonding and therefore exhibit melting points higher than any other known materials in addition to high strength, stiffness, and thermal conductivity. With such properties, these materials have potential applications in a variety of extreme environment applications such as hypersonic aircraft components and heat shields or engine nozzles for spacecraft. While much previous effort has gone into quantifying material properties of UHTCs and determining how they are affected by external factors, little work has been done to establish a fundamental understanding of how and why these materials and their properties differ at a molecular level. Utilizing molecular dynamics software, this study aims to determine how the mechanical and thermal properties of single crystal UHTCs are affected by groups of vacancy defects within the crystal structure. Specifically, Young’s modulus and the coefficient of thermal expansion of various materials were explored as loads were applied or temperatures were altered. By comparing how these materials reacted to these conditions, we ultimately hope to allow for a better understanding of how UHTCs can be combined in composite matrices to achieve the most desirable set of properties for a wide range of applications.