Structural and phase transitions in TiN-AlN and TiN-AlN-(Ni-Cr-Al) composites produced by focused solar radiation

Results are given on the effects of concentrated solar radiation on the structure and phase transitions of composite materials (CM) based on TiN-AlN. Oxidation in the TiN-AlN system leads to the formation of β-Al₂TiO₅, which prevents the diffusion of titanium and aluminum to the surface of the specimen and correspondingly is a protective barrier for the CM in air up to temperatures above 1500°C. A CM based on TiN-AlN with Ni-Cr-Al bonding has high resistance to oxidation above 1500°C. The introduction of this metal alloy into the CM favors the formation of the spinel NiCr₂O₄, which reacts with titanium and aluminum oxides to form a dense oxide film providing protection of the CM from oxidation. Then CM with compositions TiN-AlN and TiN-AlN-30% (Ni-Cr-Al) have elevated corrosion resistance above 1500°C and can be used as corrosion-resistant CM and as coatings. Translated from Novye Ogneupory, No. 9, pp. 51–53, September, 2008.