Local thermal conductivity measurements to determine the fraction of α-cristobalite in thermally grown oxides for aerospace applications

SCRIPTA MATERIALIA

卷:177

Article

Olson, David H.¹  Gaskins, John T.¹  Tomko, John A.²  Opila, Elizabeth J.²  Golden, Robert A.³  Harrington, Gregory J. K.³  Chamberlain, Adam L.³  Hopkins, Patrick E.^1,2,4 

[1] Univ Virginia, Dept Mech & Aerosp Engn, Charlottesville, VA 22904 USA

[2] Univ Virginia, Dept Mat Sci & Engn, Charlottesville, VA 22904 USA

[3] Rolls Royce Corp, Indianapolis, IN 46225 USA

[4] Univ Virginia, Dept Phys, Charlottesville, VA 22904 USA

关键词: Thermal conductivity;    Cristobalite;    Thermally grown oxide;    Environmental barrier coating;    Time-domain thermoreflectance mapping;   

DOI  :  10.1016/j.scriptamat.2019.10.027

来源: Elsevier

【 摘 要 】

Devitrification of the thermally grown oxide that forms in aerospace coatings used to protect ceramic matrix composites is a contributor to the mechanical failure of these coatings at high operating temperatures. Current methods used to identify the formation of a-cristobalite are time consuming and difficult, due to the limited differences in properties as well as the size scale over which these phase contrasts occur. This study employs time-domain thermoreflectance to spatially profile the thermal conductivity of thermally aged samples, providing a practical method to understand the spatial distribution of alpha-cristobalite in partially- and fully-devitrified amorphous silica. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

【 授权许可】

Free