The production of zirconia ceramics requires the preparation of powders with high purity, good dispersion, ultrafine particles and narrow particle size distribution. There are many preparation methods for zirconia ultrafine powders. The purification of zirconia mainly includes chlorination and thermal decomposition, and alkali metals. Oxidative decomposition method, lime melting method, plasma arc method, precipitation method, colloid method, hydrolysis method, spray pyrolysis method, and the like. The powder processing methods include a coprecipitation method, a sol-gel method, an evaporation method, a supercritical synthesis method, a microemulsion method, a hydrothermal synthesis method network, and a vapor deposition method.
forming
The zirconia ceramics are formed by dry pressing, isostatic pressing, grouting, hot die casting, tape casting, injection molding, plastic extrusion molding, colloidal solidification molding, and the like.
sintering
The sintering methods that can be used for zirconia ceramics are generally: (1) pressureless sintering, (2) hot press sintering and reactive hot press sintering, (3) hot isostatic pressing (HIP), (4) microwave sintering, (5) ultrahigh pressure sintering, and (6) discharge plasma sintering. (SPS), (7) In-situ compression molding and the like.
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In terms of structural ceramics, zirconia ceramics are widely used in the field of structural ceramics because of their high toughness, high flexural strength and high wear resistance, excellent thermal insulation properties, and thermal expansion coefficient close to that of steel. Mainly: Y-TZP grinding balls, dispersion and grinding media, nozzles, ball valve seats, zirconia molds, micro fan shafts, fiber pins, fiber sleeves, wire drawing dies and cutting tools, wear-resistant tools, case and Strap, light golf ball and other room temperature wear-resistant components.
In terms of functional ceramics, its excellent high temperature resistance is used as an induction heating tube, refractory material, and heating element. Zirconia ceramics have sensitive electrical properties and are mainly used in oxygen sensors, solid oxide fuel cells (SOFC) and high temperature heating elements. Zr02 has a high refractive index (N-21^22), and it can be made into a colorful translucent polycrystalline Zr02 material by adding certain coloring elements (V205, Mo03, Fe203, etc.) to the ultrafine zirconia powder. , like natural gemstones, sparkling with colorful light, can be made into a variety of decorations. In addition, zirconia is widely used in the fields of thermal barrier coatings, catalyst carriers, medical, health care, refractory materials, textiles, and the like.
