Atmospheric reactive plasma sprayed Fe-Al2O3-FeAl2O4 composite coating and its property evaluation

In the present study, Fe-Al2O3-FeAl2O4 composite coatings were successfully deposited by reactive plasma sprayed Al/Fe2O3 agglomerated powder. Phase composition and microstructure of the coatings were determined by XRD and SEM. The results indicated that the composite coatings were principally composed of three different phases, i.e. FeAl2O4 phase as main framework, dispersed ball-like Fe-rich phase, and small splats of Al2O3 phase, and it was thought that the in situ synthesized metal phase was helpful to toughen the coating matrix. According to the results of the indentation and frictional wear tests, the composite coating exhibited excellent toughness and anti-friction properties in comparison with conventional Al2O3 monophase coating, though its microhardness value was a little lower than that of Al2O3 coating. The formation mechanism and the toughening mechanism of the composite coating were clarified in detail.

► Fe-Al2O3-FeAl2O4 composite coatings were synthesized by atmospheric reactive plasma sprayed Al/Fe2O3 agglomerated powder. ► In situ synthesized metal phase can effectively toughen ceramic coating matrix. ► The formation and toughening mechanisms of the composite coating were clarified.