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Cold Gas Dynamic Additive Spraying of Al-Matrix Composites Coatings Reinforced by High-Entropy Oxides
In this study, BaFe12O19 and three corresponding BaFe6(AlCrTiGaCo)6O19, BaFe2(AlCrTiGaCo)10O19 and BaFe6(AlCrSnGaCo)6O19 high-entropy oxides (HEOs) particles were utilized as reinforcement particles to fabricate Al-matrix composites coatings using cold gas dynamic spraying technique. First, BaFe12O19 and HEOs reinforcement particles with a single BaFe12O19-type structure were fabricated by solid-phase sintering and ball milling. Then, Al-matrix composites with a lamellar microstructure were deposited on a steel substrate. The samples exhibited a relatively dense microstructure with low porosity consisting of BaFe12O19/HEOs particles embedded within the Al matrix. The microhardness of the composite coatings increased by increasing the content of reinforcing particles. BaFe2(AlCrTiGaCo)10O19 HEO resulted in highest microhardness values with an average value of 134 HV. This study demonstrated the effectiveness of HEOs as reinforcing particles for Al-matrix composite fabricated by cold gas dynamic spraying.