Mechanochemical Approach to Producing Ti/TiC Metal Matrix Composite Materials

Abstract

The possibilities of modifying the structure of Ti/TiC metal matrix materials by using mechanocomposites obtained by mechanochemical synthesis of titanium carbide in a reaction mixture of (Ti + C) + 70 wt.% Ti and their subsequent consolidation by pulse plasma sintering are studied using diffraction analysis and scanning electron microscopy. It is shown that in situ solid-phase synthesis of TiC_0.38 carbide in a matrix of an amorphous-crystalline α-Ti(C) solid solution is implemented within 4 – 8 min of mechanical activation in an AGO-2 planetary ball mill. With increase of the duration of the mechanical treatment from 4 to 8 min, the particle sizes of the mechanocomposites decrease by a factor of 2.6. It is shown that the sintering yields β-Ti-based composite materials with a granular structure whatever the duration of the synthesis. With increase of the duration of the synthesis from 4 to 8 min, the porosity of the material decreases from 3.14 to 2.56%, and the grain sizes of the carbide and of the β-titanium grow by a factor of 2. The materials have a Vickers hardness of 802 ± 10 HV and 749 ± 10 HV and a compressive strength of 1400 ± 50 MPa and 1600 ± 50 MPa, respectively, and a significant wear resistance. The abrasive wear coefficients of the materials attain 3.57 × 10^–5 and 2.25 × 10^–5 mm³/(N · m) respectively.