Impact of Titania nanoparticles addition on the microstructure and properties of MgO-C refractories

The main drawback of magnesia-graphite refractories is the high carbon oxidation potential at high temperatures that lead to low strength and thermochemical resistance. The aim of this study is to evaluate the impact of Titania nanoparticles addition on the microstructure and properties of magnesia-graphite refractories. 0, 0.25, 0.5, 1, 1.25 and 1.5 wt% Titania nanoparticles added to the magnesia-graphite compositions. After firing specimens at 1550 degrees C, the bulk density, apparent porosity, cold crushing strength, and oxidation resistance tests were examined. Also, crystalline phase characteristics, as well as the microstructure of sintered samples, were analyzed through the X-ray diffraction and scanning electron microscope techniques, respectively. Results revealed that Titania nanoparticles addition leads to the generation of TiN, TiC, and TiCN phases. These phases enhanced the mechanical, physical, and thermo-chemical properties of the specimens through the: (i) converting free graphite to the carbides and nitrides phases, (ii) reducing porosities in the matrix, and (iii) improving the firing process by use of nanoparticles.