Suspension and Solution Precursor Plasma and HVOF Spray: A Review

Abstract Thermal spray, being a cost- and time-efficient process, is used extensively in industrial engineering sections for mass production of desired coating structures, allowing to deposit wide range materials on various substrates. Conventionally, powder feedstocks are plasma high-velocity oxy-fuel (HVOF) thermal spray that has limitations such as limited feedstock particle size (10-100 µm), clogging options materials. Liquid feedstocks, the form suspensions or precursor solutions could potentially resolve these issues by nano- submicron particles be deposited, where unlike dry feedstock, liquid medium helps reducing friction avoiding clogging. Also, especially solutions, provide opportunity with better control over microstructure, material composition stoichiometry varying properties feedstock. Despite benefits, its own complexities, complex preparation, thermo-physical reactions during interaction energy source gases. Therefore, it becomes essential understand how different suspension solution affect microstructures properties. This review paper covers detailed discussion role process parameters properties, injection methods, torches surface affecting quality performance related recent developments challenges discussed. would beneficial optimizing obtain coatings microstructures. The later part focuses economic aspect suspension/solution precursor-based HVOF methods their applications.