Study of phase composition, microstructure and hardness of multicomponent zirconia-based ceramics

The manufacture of products from refractory ceramics requires high temperatures due to the high activation energies of the sintering process of refractory oxides. Processing temperatures for ceramics made of ZrO2, Al2O3, MgO can be reduced if a flux or glass-forming component is selected. Furthermore, in multicomponent ceramics it is possible to create more favorable thermoresistive properties. This study examines the synthesis, structural, phase and mechanical properties of multicomponent porous ZrO2-WO3-Al2O3-MgO ceramics with varying weight concentrations of components. Experimental samples were obtained by standard solid state reaction method. The analysis of fabricated samples was carried out using X-ray phase analysis, scanning electron microscopy and the Vickers microhardness test. In this work, a new approach to increasing the microhardness of porous refractory ceramics is presented, in which WO3-based flux forms a matrix composed of glass-like formations that "attach" particles of ZrO2 and MgAl2O4 phases. The obtained ceramics demonstrates high microhardness values HV0.05 for porous materials ranging from 500 to 600. Studies have shown that the selected composition of multicomponent ceramics (x = 0.10-0.25) can be used as a refractory material up to temperatures of similar to 1300 degrees C. The fabricated refractory ceramics potentially possess chemical stability and optimal microhardness properties, which makes these materials promising as a heat insulating lining in the metals, ceramics and glass manufacturing, as well as for components in the chemical industry.