The effect of low-temperature eutectics in the Ni-Ti system on the dynamics of mechanochemical synthesis of TiCx in a nickel matrix
N. S. RIDEL1, S. A. KOVALEVA2, E. T. DEVYATKINA1, S. V. VOSMERIKOV1, T. M. VIDYUK1,3, I. N. BUZMAKOV4, A. V. SIVAK4, T. F. GRIGOREVA1
1Institute of Solid State Chemistry and Mechanochemistry, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
2Joint Institute of Mechanical Engineering, National Academy of Sciences of Belarus, Minsk, Belarus
3Khristianovich Institute of Theoretical and Applied Mechanics, Siberian Branch of Russian Academy of Sciences, Novosibirsk, Russia
4TOPAZ Research Center, Moscow, Russia
Keywords: mechanochemical synthesis, mechanically stimulated reactions, titanium, titanium carbide, nickel, metal matrix composite materials
Abstract
The effect of low-temperature Ni-Ti eutectics on the mechanochemical in situ synthesis of titanium carbide in a nickel matrix has been studied by X-ray diffraction methods and X-ray spectral microanalysis. When comparing the systems containing 50 wt% Ti-(Ti-C) and 50 wt% Ni-(Ti-C), it has been determined that in the first case the induction period of reaction is 4 min, and in the second case the synthesis proceeds in a mechanically stimulated reaction mode with an induction period of 110 s and is fully completed by 120 s. By the time of reaction completion (120 s), a significant amount of TiCx (up to 38 wt%) with higher carbon content (C/Ti = 0.83) is detected in the reaction mixture with 50 wt% Ni, and the formed crystallites are larger (~30 nm) than in the mixture 50 wt% Ti + (Ti + C), which justifiably suggests a liquid-phase synthesis mechanism. In the reaction mixture with 50 wt% Ti, by 4 min of mechanical activation, up to 42 wt% TiCx with crystallite size ~9 nm is formed. In the system 50 wt% Ni-(Ti-C), the dispersed hardening of nickel with titanium carbide is enhanced by solid-solution hardening, as evidenced by the formation of Ni(Ti) solid solution within the same synthesis time intervals (120 s). Shortening of the induction period can significantly reduce the contamination of synthesis products with the material of grinding media and drum walls.
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