Abstract
Properties of detonation coatings from composite powders based on carbides are studied. The main focus is on tungsten carbide. Powders with carbide inclusions of different size ranging from a ten of microns down to the submicron level are analysed. Composites with cobalt binder content from 12 to 30 % and composite binders with chromium and nickel additions are studied. A comparative analysis between composites with chrome carbide and the complex titan-chrome carbide produced by self-propagating high–temperature synthesis is done. Powders are sprayed with a new generation detonation gun “Dragon” designed at Lavrentyev Institute of Hydrodynamics SB RAS. The apparatus is characterized by a high-precision gas supply system and a dosed localized powder feeding system. Computer control provides a flexible programmed readjustment of the detonation gases energy impact on powder particles thus allowing selecting the optimal for each material spraying parameters to form high-quality cermet composite coatings. Physical properties and functional performance of the obtained coatings are studied. Microstructure and microhardness analyses, adhesion/cohesion, abrasion, erosion and friction wear tests of the coatings are performed. It is found that the studied materials do not exhibit overwhelming advantages in performance compared with one another. Fore example, though composites with a great content of binder has a relatively low wear resistance, they exhibits the highest adhesion to the substrate while composites with titan-chrome carbide compared to tungsten carbide-based composites have higher dry friction and lower lubricated friction.
