Optimizing of hardness, microstructure and adhesive strength of plasma-sprayed FeSiAl coatings using orthogonal analysis

The traditional high-efficiency absorber FeSiAl has gradually achieved the attention at high temperature. The paper focuses mainly on the preparation and characterization of plasma-sprayed FeSiAl coatings. The plasma-sprayed FeSiAl coatings were prepared through the Praxair 100HE high enthalpy plasma spray gun on stainless steel 316 substrate by orthogonal experiment. The cross-section and properties of sprayed coatings were analyzed. The results reveal that the best parameters of sprayed coatings can be represented by C3B2A3D2 for microhardness, i.e., 30 SCFH, 140 mm, 50 KW, 3 PRM. The optimal parameters can be expressed as C3D1B3A3 for adhesive strength, i.e., 30 SCFH, 2 PRM, 200 mm, 50KW. The cross-section of sprayed coatings is composed of fattening FeSiAl particles (pale gray) and oxidation phase of FeSiAl (dark). The percentage of disorder structure reduces in FeSiAl coatings.