Effect of Pyrolysis Temperature on Electrical Properties and Conduction Mechanism of Polymer-Derived SiC Ceramics
Abstract
Silicon carbide (SiC) is a typical non-oxide refractory ceramic material with properties such as high melting point, oxidation resistance, chemical and thermal stability, high hardness and strength, etc. Traditional manufacturing process of SiC is to combine SiO2 and carbon in an Acheson graphite electric resistance furnace at a high temperature between 1600oC and 2500oC, where the crystal structure is formed at temperatures about I 700oC. Effect of pyrolysis temperature over a span of temperature range (e.g., IO00oC-2000oC) on the evolution of its microstructure and in turn electrical properties has not been systematically studied. It will be the motivation of this study. Electrical properties include DC conductivity, AC conductivity, permittivity and loss tangent factor. The SiC in this study will be produced via the pre-ceramic precursor route which allows the formation of such ceramics over a broad final processing temperature range. The microstructure and chemical compositions of such polymer-derived ceramics are determined by the final pyrolysis temperature and independent of its application temperature, as long as the application temperature is below the final pyrolysis temperature; but its electrical properties are affected by its application temperature and are temperature-dependent. This proposal is to systematically study the effect of pyrolysis temperature (e.g., I000oC-2000oC) on electrical properties of polymer-derived SiC ceramic materials. Different pyrolysis temperatures produce different microstructures, which will result in different electrical properties and in turn different conduction mechanism behaviors. Successful delivery of this project will provide a fundamental guideline in modifying material s electrical properties, and will have many potential uses for bulk structural components with multifunctional capabilities in field assisted sintering techniques such as flash assisted sintering or spark plasma sintering.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 11, 2018
- Source ID
- W911NF1710570
Entities
People
- Chengying Xu
Organizations
- Army Contracting Command
- Florida State University
- United States Army