Effect of Properties of Titanium Aluminide Powders and Detonation Spraying Conditions on Phase and Structure Formation in Coatings

We have studied phase formation in detonation coatings sprayed from Ti - 50 at.% Al powders. The powders of the alloy were obtained by various methods: crushing an ingot and mechanical alloying of Ti and Al. Using polyphase nanostructural materials activated by mechanical alloying makes the process of phase formation in the gas-thermal sprayed coatings based on them more general-purpose and controlled due to the more active and more subtle reaction of the material with the gaseous atmosphere. We have shown that from mechanically alloyed Ti - 50 at.% Al powder, using the detonation-gas spraying method we can consolidate a coating based on Al₂TiO₅ by oxidizing action of the working gas on the powder and also a coating based on titanium aluminides with TiN inclusions by nitriding action. The phase composition of the cast microstructural γ-TiAl powder is inherited by the coating.