Synthesis and characterization of high-strength ceramic composites in the system of potassium titanate – Metallurgical slag

Ceramic composites based on different mixtures of the powdered slags from silicomanganese manufacturing and synthetic potassium titanates, were produced and investigated. Green bodies were fabricated by uni-axial compression at 35 and 196 MPa. The sinters were obtained by one-stage (1100 °C/1 h) or two-stage (800 °C/1 h and 1100 °C/1 h) thermal regimes. The best mechanical properties were achieved for conditions of 33 wt% of slag, compressed under 196 MPa and treated by the two-stage regime of sintering. Structural investigation of the processes taking place in the produced ceramic materials was carried out by scanning electron microscopy and X-ray diffraction. The resulting products were characterized by a gradient phase composition constituted by perovskite, leucite, potassium hexatitanate, pyrophanite-ilmenite solid solutions, hollanadite-like and pyroxene-like crystalline phases as well as glassy phase of varied chemical composition. The mechanism of the sintering processes was also characterized.