Structure and Thermophysical Characteristic of Compacted Graphite Cast Iron Composite Castings Reinforced with (Ti, Mo)C

This work deals with the development of new Compacted Graphite Cast Iron Composite Castings as an alternative to Si–Mo ductile iron. The new material is a silicon-molybdenum cast iron (Si–Mo), transformed into a cast composite using the Self-propagating High-temperature Synthesis in Bath (SHSB) method, which synthesizes ceramic carbide particles of metals such as Ti, W, Nb, Mo, Zr. SHSB is used to ensure the formation of thermodynamically stable ceramic phases, in this case, carbide phases. Among the listed metals, titanium was selected for the SHSB synthesis process due to the exceptionally favorable physicochemical properties of titanium carbide and its highly exothermic enthalpy of formation. The described process strengthens the matrix of the material, changing its characteristic operational properties. The resulting composite is designated as Si–Mo TiC. Conventional Si–Mo cast iron is widely applied in the automotive industry, where it is used, for instance, in the production of exhaust manifolds and turbocharger components, where high resistance to thermal shock and excellent heat resistance are required. Transforming this material into a composite material improves many physicochemical parameters. Additionally, titanium desferoidizing effect helps stabilize graphite in the compacted (vermicular) form. Castings of both conventional Si–Mo iron and the TiC-reinforced Si–Mo composite with compacted graphite were produced with varying wall thicknesses. The microstructural characteristics and thermophysical properties, such as thermal conductivity and thermal stability, of the classical and composite materials were compared. The new Si–Mo cast iron reinforced with thermally stable TiC particles has been demonstrated to exhibit excellent structural integrity and thermal stability.