Plasma Spray Fe_3Al-Al_2O_3 Graded Coatings

摘要

Fe_3Al intermetallic powder was produced by mechanical alloying method. It was mixed with Al_2O_3 powder to get Fe_3Al/Al_2O_3 composite powder with different components. Three types of Fe_3Al/Al_2O_3 coatings, which are called double layered coatings (DC), triple layered coatings (TC) and graded coatings (GC), were produced on low carbon steel substrate by plasma spray. The microstmcture and component distribution were studied by techniques including optical microscope, SEM, XRD and electron probe. The adhesive strength and thermal-shock resistance of the coatings were also tested. The results show that graded coatings can be produced from layered design. The graded coatings have higher adhesive strength and thermal-shock resistance. Fe_3Al intermetallic is a kind of excellent transition material between ceramic coatings and carbon steel substrate.