Production of metal matrix composite reinforced by TiC by reactive infiltration of cast iron into Ti + C preforms

The high-temperature interaction between molten gray cast iron and Ti + C substrates that are composed of titanium and graphite powders was investigated by the sessile drop method combined with the non-contact heating of an alloy/substrate couple to a test temperature of 1330 °C in an inert gas atmosphere (argon). During the high-temperature testing, the images of the couple were recorded by a high-speed high-resolution CCD camera and used for estimating the values of the contact angles over time. An analysis of the wettability kinetics of the different Ti + C substrates by molten cast iron as well as a detailed structural characterization of the solidified couples with the help of light microscopy, electron microscopy (SEM, TEM), X-ray diffraction, and energy-dispersive X-ray spectroscopy have allowed us to explain the mechanism of high-temperature interaction in the selected couples. It was evidenced that the good wetting and fast infiltration of all of the examined substrates with the selected alloy had a reactive nature due to the dissolution of the Ti and graphite in the molten alloy (dissolutive wetting) and the reactively formed wettable TiC phase. These high-temperature phenomena contributed to the formation of three metal-infiltrated zones with different amounts and distributions of TiC particles in the Fe-based matrix.