Novel Ti2CuCx and Ti3Cu2Cx carbides obtained by sintering of products of mechanochemical synthesis of Ti, Cu and carbon nanotubes

Abstract

Mechanical alloying of the elemental powder mixture of titanium and copper (particle size of both powders is about 40 μm, purity is not less than 99.6% wt. %) was performed in a high energy planetary ball mill to obtain Ti:Cu (2:1 and 3:1) compositions. An addition of 1 vol. % of multiwalled carbon nanotubes (MWCNT, average diameter 10-20 nm) into Ti-Cu charge results in a formation of nanoscaled Ti2CuCx and Ti3Cu2Cx carbides (containing 0.5 and 4.2 at.% of carbon and 30.8 and 37.5 at.% of copper, respectively). These carbides have synthesized for the first time. Nature of interaction of the charge components at processing in a ball mill has studied on test samples using a complex of X-ray techniques. These techniques include a full-profile analysis for the primary processing of diffractograms obtained with DRON-3M apparatus; qualitative and quantitative phase analysis for determining the phase composition of the products of synthesis; X-ray structural analysis to verify and refine the structural models; Williamson-Hall method for determining the grain sizes. The Vickers hardness of compacted (by sintering) samples with 20.1 and 27.3 at. % Cu varies substantially within (6.9-7.1) GPa. Thus, the average microhardness of synthesized materials is 7 times higher than that of pure titanium microhardness.