Articles
  • Thermal and mechanical properties of C/SiC composites fabricated by liquid silicon infiltration with nitric acid surface-treated carbon fibers
  • Jae Hyung Choi, Seyoung Kim*, Soo-hyun Kim, In-sub Han, Young-hoon Seong and Hyung Joon Bang
  • Energy Material Laboratory, Korea Institute of Energy Research, 152 Gajung-ro Yuseong-gu Daejeon, Korea
Abstract
Carbon fiber reinforced SiC composites (C/SiC) have high-temperature stability and excellent thermal shock resistance, and are currently being applied in extreme environments, for example, as aerospace propulsion parts or in high-performance brake systems. However, their low thermal conductivity, compared to metallic materials, are an obstacle to energy efficiency improvements via utilization of regenerative cooling systems. In order to solve this problem, the present study investigated the bonding strength between carbon fiber and matrix material within ceramic matrix composite (CMC) materials, demonstrating the relation between the microstructure and bonding, and showing that the mechanical properties and thermal conductivity may be improved by treatment of the carbon fibers. When fiber surface was treated with a nitric acid solution, the observed segment crack areas within the subsequently generated CMC increased from 6 to 10%; moreover, it was possible to enhance the thermal conductivity from 10.5 to 14 W/m·K, via the same approach. However, fiber surface treatment tends to cause mechanical damage of the final composite material by fiber etching.

Keywords: C/SiC composites, LSI process, Surface treatment, Thermal conductivity, Mechanical properties

This Article

  • 2019; 20(1): 48-53

    Published on Feb 28, 2019