Atmospheric Plasma Spray Processes: From Micro to Nanostructures

Abstract

Atmospheric plasma spray is probably the most versatile of all thermal spraying processes, because there are few limitations either on the materials that can be sprayed or the substrate, in relation to its material, size, and shape. The material precursor of the coating could be in the form of powders, wires, melted materials, solutions, or suspensions. What distinguishes the plasma spray process from other technologies is its applicability and capacity to process a wide variety of materials, including metallic and refractory materials at atmospheric pressure. The coatings properties are improved by deposition of coatings with finer microstructure, which is are more suitable for mechanical and thermal stresses than the lamellar microstructure of conventional plasma-sprayed coatings.

Coating solutions for enhancing automotive brake disc durability against corrosion and wear—a review

“…The thermal spray process is a highly versatile and widely employed coating technique utilized across industries. It serves as a cornerstone in the realm of surface engineering, allowing for the precise and controlled application of coatings to various substrates [48,49]. This process hinges on the fundamental principle of transforming coating materials, typically in powder or wire form, into a molten or semi-molten state.…”

Palladium Membrane with High Density of Large-Angle Grain Boundaries to Promote Hydrogen Diffusivity

“…It is necessary to adjust the injection parameters to ensure that the momentum of the particles is equal to the momentum of the plasma jet. In this way, the suspension bounces back from the plasma surface or crosses the plasma completely, and instead reaches the jet core [68]. Figure 1a-d summarizes the influence of the injection pressure used in the argon pressured tank (4 vs. 9 bar) for feeding the suspension to the jet and of the injection nozzle aperture used (0.2 mm vs. 0.3 mm).…”

Review of the coatings used for brake discs regarding their wear resistance and environmental effect

“…70 Atmospheric plasma spraying (APS) is a technique where the dispersed material is heated by plasma and further directed (sprayed) towards the surface to be coated, so the material (coating) is deposited on the substrate, and a coating is formed. 71 According to 72 the material used for coating must be in the form of a powder which must be flowable. Research indicates that the thickness of the coating layer ranges from 100 µm up to a few millimeters.…”

“…Research indicates that the thickness of the coating layer ranges from 100 µm up to a few millimeters. 71 The coating process, in this case, is influenced by various parameters determined by the application parameters (particle application rate, plasma temperature,…), but also by the characteristics of the applied powder. 73 Bearing in mind that very high temperatures are reached during the application of this method, surfaces can be coated with materials that have a high melting point.…”