SPS of ”Titanium Carbide/Carbohydride – Copper” Composites

The TiC-copper and Ti2CH0.6-TiC-intermetallic Cu-Ti composites were produced using high-energy wet ball milling of Ti-Cu-graphite and Ti-Cu-surfactant powders, respectively, followed by spark plasma sintering at 900∘С. The composites were shown to be of 91-92% in density as compared with the theoretical value, microhardness of 6-7 GPa, and elasticity modulus of 134-140 GPa. The tribological properties of the composites were shown to depend on the phase composition. Surfactant addition resulted in higher fretting resistance against tempered steel (С-1%, Сr-1.5%) due to the formation of hexagonal titanium carbohydride and higher abrasive wear resistance.     Keywords: titanium carbide; titanium carbohydride, composite; ball milling; spark plasma sinterin

Peculiarities of phase formation in the mechanosynthesized titanium carbohydride powders under short pulse selective laser alloying

The authors analyze peculiarities of the phase formation and morphology of the titanium carbohydride coatings deposited on the steel substrates by means of short pulse selective laser alloying. Ti(C,H) powders with a particle size of 0.5–5 μm have been preliminarily produced by mechanical activation of titanium in petroleum ether. Heating up to 900°C results in the decomposition of the titanium carbohydride with the formation of TiC and Ti. The coatings deposited under laser alloying of carbohydride and steel substrate contain 50 vol.% of the “core–shell” inclusions with TiC as a core and TiFe2 and TiFe intermetallic compounds as a shell. Inclusions are of rounded shape both with a size of 50 to 200 nm, and the dendritic one is of up to 5 μm. Coatings up to 10 microns thick have a gradient pore-free structure and do not wear out under dry friction on hardened steel. Their microhardness is of 1016 HV, with a friction coefficient being 0.2. The proposed new in-situ technique for producing titanium-carbide-based coatings may be used for developing other metal carbide coatings with high performance characteristics