Mechanical and Tribological behaviour of velocity oxygen fuel thermal spray coating: A Review

Abstract

For over decades thermal spraying has been present and optimized over the time and now it has become an effective method to thick coating deposition. Thermal spray coating especially high velocity oxygen fuel (HVOF) have served various industrial sector such as aerospace, defence and thermal electricity generation. To overcome disadvantages of traditional coating there was a need of smart coating process which could integrate new functionalities and coherent responses. The aim of this paper is to present a detailed review of current technological changes in HVOF thermal spray coatings. This paper gives insight view of different type of coatings on substrates, their mechanical and tribological properties. HVOF coating categorised according to various application sector has also been discussed in this paper.

Oxidation Behavior of FeNiCoCrMo0.5Al1.3 High-Entropy Alloy Powder

“…One of the most promising applications of AlCoCrFeNi HEA is the fabrication of protective coatings [13,14]. HEA-based coatings, deposited on medium-carbon steel substrates, can considerably enhance the material performances, extend service life, and reduce product costs [13][14][15]. Thick coatings with low porosity and a high level of adhesion can be produced via the high velocity fuel spraying (HVOF) technique [13,15].…”

“…HEA-based coatings, deposited on medium-carbon steel substrates, can considerably enhance the material performances, extend service life, and reduce product costs [13][14][15]. Thick coatings with low porosity and a high level of adhesion can be produced via the high velocity fuel spraying (HVOF) technique [13,15]. HVOF is a combustion spray process in which a hydrocarbon fuel (kerosene, methane, propane, etc.)…”

“…HVOF is a combustion spray process in which a hydrocarbon fuel (kerosene, methane, propane, etc.) is ignited, mixing with oxygen to accelerate feedstock powder towards the substrate [13,15]. Depending on the particle's size and location in the high-temperature flow, the particles undergo various transformations, such as melting, softening, spheroidization, precipitation, and surface or total oxidation, similar to those observed with the atmospheric plasma spraying (APS) method [14].…”

“…A unique feature of thermal spray processes is the extremely high heating and cooling rates (>10 6 K/s) [13][14][15]. Such rapid cooling rates result in a fine-grain and non-equilibrium structure due to the prevention of elemental segregation [13][14][15].…”

“…A unique feature of thermal spray processes is the extremely high heating and cooling rates (>10 6 K/s) [13][14][15]. Such rapid cooling rates result in a fine-grain and non-equilibrium structure due to the prevention of elemental segregation [13][14][15]. The feedstock powders most commonly used for thermal spraying are highly nonequilibrium structures produced by mechanical alloying or gas atomization that undergo phase changes when heated [22][23][24].…”