Oxidation of carbon/carbon composite coated with SiC-( Si ZrSi2)-ZrSi2
Journal
Carbon
Journal Volume
32
Journal Issue
4
Pages
605-613
Date Issued
1994
Author(s)
Abstract
A multi-layer coating of SiC-( Si ZrSi2)-ZrSi2 was deposited on carbon/carbon composite (C/C) to improve resistance to oxidation. The coating layer after controlled oxidation, which converted its surface to oxides, provided a passive function on exposure to an oxidizing atmosphere at high temperature. The oxidation properties of the composite were tested by thermogravimetric analysis (TGA) up to 1400°C, static and cyclic oxidation tests, and a thermal ablation test with a plasma jet in the atmosphere. Microstructural analysis, including scanning electron microscopy (SEM) and X-ray mapping, was used to reveal the features of the coating layer with and without oxidation. TGA measurement revealed that C/C coated with SiC-( Si ZrSi2)-ZrSi2 underwent moderate oxidation up to 1000°C, but experienced less loss of mass above 1000°C. Zircon (ZrSiO4), cristobalite (SiO2), and zirconia (ZrO2) were found in the oxidized layer of the coating. The multi-layer coating significantly improved the resistance to thermal ablation and cyclic oxidation of C/C, and was superior to singlelayer SiC-coated C/C and copper-infiltrated tungsten composites. © 1994.
Type
journal article