Energy Carrier Transport in Advanced Structural Materials for Thermal Management
Abstract
Integrating thermoelectric conversion functionality directly into structural materials would enable direct conversion of heat into electricity or highly localized cooling/heating onboard aircraft, weapons, and ships. Increasing interface density (or reducing grain size) substantially improves thermoelectric properties. Interfaces introduce phonon scattering sites or enable low energy electron filtering, thus decreasing thermal transport or increasing thermoelectric power factor, respectively. The challenge with increasing interface density in thermoelectric materials lies in materials processing. Techniques such as ball milling and melt spinning create particulate material with small features. However, this particulate material must be consolidated in a subsequent step such as hot pressing; the consolidation eliminates the interfaces as particles melt together and grains grow. There is a need for a technique which creates interfaces in situ during consolidation. Such an approach would enable interface engineering to improve performance.The objective of the project proposed here is to use laser melting as a mechanism to engineer interfaces in thermoelectric materials while simultaneously achieving consolidation. The research approach aims to determine the impact of laser-processed thermoelectric material interfaces on thermal and electrical transport properties as well as mechanical properties. The work will determine if increasing interface density will cause the thermal conductivity to decrease, the power factor to increase, and the strength to increase. The work will focus on silicon germanium alloys, a high temperature thermoelectric material in which the majority of the thermal conductivity is due to phonon transport, so interfaces can introduce phonon scattering sites and decrease the thermal conductivity. The proposed approach could intersect with the advances in laser additive manufacturing such as laser powder bed fusion to create multifunctional materials with adaptable geometries. Implemented in high temperature applications, these multifunctional materials could provide power generation or thermal management capabilities, thus improving vehicle energy efficiency and reducing the need for auxiliary energy storage or electricity production systems.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 20, 2020
- Source ID
- N000142012365
Entities
People
- Saniya LeBlanc
Organizations
- George Washington University
- Office of Naval Research
- United States Navy