• Babul, T.
• Bojar, Zbigniew
• Senderowski, Cezary

Abstract

<p>The aim of this paper is to present the results of detailed research of the application of Detonation Gun Spraying process (D-gun) for deposition of Fe-Al intermetallic coatings in the presence of NiAl and NiCr interlayers. A number of D-gun experiments has been carried out with significantly changed operational spraying parameters (the volume of the working gas, fuel gas, distance and the frequency of spraying) which define the process energy level directly influencing the quality of the coating. On the basis of the initial results the choice of the process parameters has been made to obtain the most advantageous set of geometric and physical-mechanical properties of the coating material, interlayer and substrate. The metallurgical quality of the coatings was considered by taking into account the grain morphology, inhomogeneity of chemical content and phase structure, cohesive porosity in the coating volume, as well as adhesive porosity in the substrate/interlayer/coating boundaries. The surface porosity level was also considered. It was found that the D-gun sprayed coatings, in all cases are built with flat lamellar splats resulting from the powder particles which are D-gun transformed in their plasticity and geometry. A significant result of the optimisation of D-gun spraying parameters is the lack of signs of melting of the material (even in microareas) while the geometry of the subsequently deposited grains is considerably changed and the adhesivity and cohesion of the layers proves to be high. This has been considered as an undeniable proof of high plasticity of the GDS formed Fe-Al intermetallic coating.</p>

Topics

• Deposition
• impedance spectroscopy
• morphology
• surface
• grain
• phase
• experiment
• plasticity
• porosity
• intermetallic