Scale resistance of titanium silicide – titanium aluminide powder composites

A scientific team consisting of employees of the Laboratory of Physics of Consolidation of Powder Materials conducted a study of the microstructure and phase composition of synthesis products obtained in the gasless combustion mode of reaction powder mixtures of titanium, aluminum and silicon (Ti₅Si< sub>3+10-40 wt.% Al). It was revealed that the combustion temperature depends on the aluminum content in the reaction mixtures: with increasing aluminum content, Tg decreases monotonically. The synthesis products in powder mixtures of titanium, silicon and aluminum are a composite of two refractory compounds: titanium silicide Ti₅Si₃ and titanium trialaluminide TiAl₃ . The relative content of silicide and aluminide, the dispersion of the structure and the degree of defectiveness of the composite granules depend on the aluminum content in the reaction powder mixtures.

Figure - Microstructure of synthesis products in reaction mixtures with different aluminum content (wt.%): (a) 0%; (b) 10%; (in 20%; (d) 30%; (e) 40%; (f) composition of the mixture 3Al + Ti

The resistance of composites to oxidation when heated in air in the temperature range 600-1100°C was determined. The scale resistance of the synthesized powder composites is determined to a greater extent by the defective structure of the granules (pores and cracks), rather than by their phase composition.

The composition of the reaction mixture has been established, the synthesis products in which have a scale resistance 1.5-3 times higher (mixture No. 2 - Ti₅Si₃ + 20% Al) than in other studied composites, as well as in single-phase silicide and trialuminide. Composite powders synthesized from a mixture of this composition are of practical interest as feedstocks for spraying scale-resistant coatings on titanium and its alloys.

The work was carried out within the framework of the state assignment of the Institute of Physical Problems and Problems of the Siberian Branch of the Russian Academy of Sciences, topic number FWRW-2021-0005

G.A. Pribytkov, V.V. Korzhova, I.A. Firsina, A.V. Baranovskiy, and V.P. Krivopalov. Scale Resistance of Titanium Silicide Ti₅Si-Titanium-Aluminide TiAl₃ Powder Composites. Protection of Metals and Physical Chemistry of Surfaces, 2023, Vol. 59, No. 2, pp. 265-271.
https://doi.org/10.1134/S2070205123700223 (Impact Factor 0.943, Q2 Scopus)< /p>