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Fe(Co) composite locally reinforced with in situ TiC particulates was successfully synthesised utilizing the mechanochemical and self-propagating high temperature synthesis (SHS) reaction of FeTi-Co-C system. The microstructure of the Fe(Co)/TiC composite was investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD). With the help of differential thermal analysis (DTA), the reaction path of the FeTi-Co-C system was studied. X-ray patterns exhibited gradual formation of TiC during 5-10 h milling process. DTA results indicated that Co has considerable effects on thermal behaviour of this system, which reduced ignition temperature to 1025uC. By comparing these results, it was found that the Fe(Co)-TiC composite could be fabricated using both methods although finer structure and better reinforcement dispersion was obtained via mechanochemical technique.

In this study, the synthesis of ZrB2/SiC composite was carried out via infiltration of silicon melt into a ZrSiO4/B4C preform, and the effect of different ratios of ZrSiO4/B4C and C/ZrSiO4 was investigated on phase and microstructural properties. For this purpose, stoichiometric ratios of raw materials and 10 wt% phenolic resin were used to induce the porosities in the preform. Then the powder mixture was milled and pressed. To perform pyrolysis reaction, it was placed in a vacuum-controlled atmosphere furnace with argon gas at 650 °C and then the Si infiltration process was performed at 1650 °C for 1 h. The hardness, density, and elastic modulus of the samples were measured. The optimum results were obtained for the composite sample with a ZrSiO4/B4C ratio of 4, which had a density of 5.28 g cm−3, elastic modulus of 423 GPa, and hardness of 33.28 GPa. Moreover, scanning electron microscopy and x-ray diffraction analyses confirmed a uniform distribution of ZrB2 and SiC phases and the absence of undesirable phases in the sample, respectively.