Abstract
FeAl intermetallics matrix composites reinforced by ceramics particles such as titanium carbide have attracted much attention in recent years. In this study, shrouded plasma spraying with nitrogen as a protective gas was employed to deposit TiC particles dispersed FeAl/TiC composite coatings. Fe-35Al powder and Fe-35Al/TiC composite powders containing 35 vol.% and 45 vol.% TiC prepared by mechanical alloying were used as feedstock powders. The microstructure of the ball-milled powders and the as-sprayed coatings was characterized by scanning electron microscopy and X-ray diffraction. The mean coefficient of thermal expansion (CTE) of FeAl and FeAl/TiC was measured. The results showed that dense FeAl and FeAl/TiC coatings with low oxide inclusions were deposited by shrouded plasma spraying. The mean CTEs calculated based on the Reuss formula are reasonably consistent with those measured in the present study. As a result, the CTE of FeAl-based composite coating can be properly controlled by adjusting TiC content in the composite coating to match with that of the substrate.
