Hybrid TiC–Graphite–Bronze Composites Obtained by the SHS Method: Structure, Strength, Tribology

The paper investigates the possibility of spontaneous infiltration of molten copper and bronze BrAZh 9-4 into porous TiC and TiC-graphite frameworks obtained by self-propagating high-temperature synthesis (SHS) in open air. The features of interphase interaction of copper and bronze melts with a temperature of 1200°C with hotter TiC and graphite frameworks after SHS (>2500°C) have been studied. The density of the obtained TiC–BrAZh and TiC–C(graphite)–BrAZh composites is 6.18 and 5.10 g/cm3, respectively. It was established that infiltration and wetting of copper and bronze melts is accompanied by partial dissolution of titanium in the melt, which indicates the reactive nature of the interaction. Intensive infiltration limits the SHS process of TiC, leaving part of the carbon in a free form. Titanium dissolved in copper precipitates on the surface of TiC and graphite particles, forming a dense crust of non-stoichiometric TiCx around these particles. Tribological studies have shown that the addition of graphite to the TiC–BrAZh composite reduces hardness by 2.7 times, elasticity by 2.2 times, and yield strength by 1.7 times. However, it increases wear resistance by 1.5 times and reduces the instability of the friction coefficient by 0.1 with the same level of its average value.