X-ray and EPR study of reactions between B4C and TiO2

X-ray diffraction and electron paramagnetic resonance (EPR) methods have been used to study the reaction process in a system of 95 wt.% of B4C + 5 wt.% TiO2. The addition of TiO2 to B4C was effective in accelerating the removal of carbon inclusions. Two types of reactions between B4C and TiO2, starting at temperatures ∼1173 K, took place: (a) gas-transport exchange and (b) diffusion of Ti atoms into the B4C lattice. These reactions modify the number and type of donor centers in the B4C. The dependence of EPR line width on the number of donor centers in B4C (from conditions of sample treatment) is a useful method for investigating the formation of powders and ceramics based on B4C.