BY SILICON NITRIDE MODIFIED MULLITE-ZRO2 CERAMICS

摘要

The invention relates to high-temperature chemically inert, high hardness and high mechanical strength products for use in several sectors of the economy, particularly in construction, engineering, chemical industry, food processing technology cycle, also in medicine.The aim of the proposed invention is a high strength, thermal shock resistant mullite 3Al2O3·2SiO2-ZrO2-Si3N4 composite ceramics from nanopowders output by use of spark plasma sintering (SPS) method.High strength and thermal shock resistant with silicon nitride modified mullite-ZrO2 ceramics is obtained from the mixture of powder containing (wt %) gamma Al2O3 52.0 to 62.0; quartz sand 25.5 to 28.0; ZrO2 (monoclinic) 4.2 to 5.2; Y2O3 4.0 to 4.8; and plasma synthesized silicon nitride nanopowder Si3N4 1 to 10. Ceramic is formed by unconventional SPS process up to a maximum temperature of 1400–1500 °C.The new type of ceramic material differs with set of improved functional properties (high compression and the the thermal shock resistance, elasticity module indicators, as well as the chemical durability to aggressive environments).