Multicomponent Diffusion Coatings Based on Titanium, Aluminum and Silicon on the Nickel

Abstract

The results of the research phase and chemical composition, structure, microhardness multicomponent coatings involving titanium, aluminum, silicon on nickel are given. The coating was applied to the mixture of powders of titanium, aluminum, silicon, inert additives Al₂O₃, activator NH₄Cl, in containers with fusible shutter under reduced pressure at the temperature of 1050 °C, for 4 hours. The influence of composition of the saturating mixture on the phase, chemical composition, structure, microhardness zone compounds and transition zone on nickel was established. It is shown that diffusion coatings consist of zone connections and the transition zone, which is a solid solution saturating elements in nickel. When alumosiliconizing in the zone of compounds includes intermetallic compounds NiAl, Ni₃Al; when titanium-alumosiliconizing – Ni₂Ti₄O, NiTi, NiTi₃, Ti₅Si₃, Ni₃Ti, Ni₁₆Si₇Ti₆.The detected presence in the transition zone when alumosiliconizing – aluminum, silicon, oxygen; when titanium-alumosiliconizing – titanium, aluminum, silicon. The maximum microhardness is set for zone of connection with the participation of titanium, aluminum, silicon is 12.5 GPa. The obtained coating composition, structure and properties involving titanium, aluminum, silicon on nickel can be promising when operating in conditions of high temperatures, corrosive environments.