EFFECT OF GAS MEDIA ON THE STRUCTURAL EVOLUTION AND PHASE COMPOSITION OF DETONATION COATINGS SPRAYED FROM MECHANICALLY ALLOYED Ti-Al-B POWDERS

摘要

The paper examines the phase formation of detonation coatings sprayed from mechanically alloyed Ti-50 Al-25 B powder. It is shown that coatings with different phase compositions and functional properties can be consolidated from this activated powder by varying process conditions (including gas composition during detonation spraying). Three types of composite coatings with different structures are obtained: TiB and TiB_2 inclusions are distributed in an intermetallic matrix (Al_3Ti,γ-TiAl) inclusions of oxides and oxynitrides are additionally present in the same structure; inclusions of borides, Al, and Ti are distributed in a mixture of intermetallic and nitride (TiN, AlN) phases.