Thermal Characterization Of As4/3501-6 Carbon-Epoxy Composite

Bradley R. Doleman, North Carolina Agricultural and Technical State University

Abstract

Thermal diffusivity, specific heat, and thermal conductivity are important thermophysical properties of composite materials and foams. Thermal characterization provides these material properties which play a significant role in the engineering design process of space systems, aerospace vehicles, transportation, energy storage devices, and power generation including fuel cells. Thermal conductivity is the parameter that is important in problems involving heat transfer and thermal structures. Because it determines the working temperature levels of a material, the thermal conductivity is critical when considering the performance of materials in high temperature applications as well as safety, process control, and quality assurance. As a result of the scarce thermal property data for the AS4/3501-6 carbon-epoxy composite, this research has developed the thermophysical property database. Using the xenon flash method in accordance with the ASTM E1461 standard, the thermal diffusivity was measured through the thickness. Differential scanning calorimetry (DSC) was used to measure the specific heat in accordance with the ASTM E1269 standard. Both of these properties were measured from room temperature up to the service temperature range of the material. The AS4 composite is recommended for general purpose structural applications. The epoxy matrix is amine cured up to the service temperature of 175 C, and the composite was made using the high pressure autoclave process. After measuring the specific heat and thermal diffusivity, the thermal conductivity was calculated using a directly proportional relationship between the density, specific heat, and thermal diffusivity, thus adding to the currently insufficient thermal properties database for composite materials and foams.