Oxidation Control of Atmospheric Plasma Sprayed FeAl Intermetallic Coatings Using Dry-Ice Blasting

Thermal spray process was considered as one of efficient methods for forming FeAl intermetallic coatings. But the performance of thermally sprayed FeAl coatings was remarkably limited because of oxidation, phase transformation and nano-structured grain growth during the preparation. In the present work FeAl intermetallic coatings were obtained by means of atmospheric plasma spray combined with dry-ice blasting. Dry-ice blasting, as an environmental-friendly and cryogenic method, is potential to control the oxidation level and the grain scale. The oxidation level has been studied by using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) as well. TEM has also been employed to illustrate the grain size and even to reveal the degree of the compound ordering in the as-sprayed coating.