Formation of intermetallic Ni–Al coatings by mechanical alloying on the different hardness substrates

• Chemical composition of substrate affects the phase transformation of the coatings.
• High hardness substrates add big amount of materials from its surface to the powder mixtures.
• Low hardness substrates add small amount of materials from its surface to the powder mixtures.
• Substrate microhardness under coating layer increases in case of low hardness substrates.
• Subsequent annealing of the as-coated samples leads to homogeneity intermetallic phases.

The objective of the study was production and investigation of durable Ni–Al intermetallic coatings on metallic substrates by mechanical alloying method depending on substrates properties. It was shown that the chemical composition and hardness of substrate material affect the phase composition of coatings. In the course of mechanical alloying, the phase composition of coatings shifts in the direction of enriching it with the main component of the metallic substrate. During subsequent annealing of the as-coated samples homogenous intermetallic phases were formed on the surface as the result of interdiffusion between components.