Control Of The Grain Growth Of Zirconia Ceramics

Tetragonal Zirconia Polycrystal (TZP) stabilized with Y₂O₃ (Y-TZP) is widely used because of its good mechanical properties. This kind of material is usually fabricated at high temperatures, e.g., at 1550-1650 °C. The high sintering temperature not only causes high production cost, but also makes the grain size coarse, which reduces its mechanical properties and limits its application. The aim of the present study was to obtain a kind of Y-TZP material with comprehensive mechanical properties via low temperature sintering by various means.The effects of the grain size of 3Y-TZP on material performance and the factors that affect the grain size of zirconia were analyzed. The pre-heat treatment, de-agglomerating of powders, powder surface modification and classification were studied by using SG3-TZP-Q ultra fine powders produced by SHENZHEN NANBO STRUCTURE CERAMICS CO., LTD. Low temperature sintering of 3Y-TZP was realized after adding appropriate additives, and growth of the grain size was controlled.The main conclusions of the research are as follows:Temperatures if over 500°C for pre-heat treatment of 3Y-TZP powders would result in powder neck-growth and cause the particle size being coarse and grain size distribution range being wide.Some powder agglomeration could be broken by mechanochemical method with surface modification. The powders were changed from polarity to non-polarity. The organic molecules were absorbed on the surface of particles of 3Y-TZP and thus the reuniting of particles was avoided after being de-agglomerated. The fluidity of the treated powders increased and...