Shape memory ceramic and its prepn

Abstract

The shape memory ceramic contains ZrO2 as base material, Ce and Y and consists of CeO2 7-10 mol%, preferably 7.5-8.5 mol%, Y2O3 0.2-0.8 mol%, preferably 0.45-0.55 mol%, and ZrO2 the rest. The preparation process includes the following steps: preparing superfine powder of the components via coprecipitation, sintering at 1500 deg.c for 4-6 hr, cooling gradually to obtain tetragonal crystal system of polycrystalline zirconia ceramic block with crystalline grain size 0.9-1.1 micron and density 5.9-6.1 g / cu cm. The shape memory ceramic has shape recovering rate of 95-100 % in strain up to 1.2 %,high action temperature and pseudo-elastic recovery of 3-4 %.

Description

technical field

[0001] The invention relates to a shape memory ceramic, in particular to a shape memory ceramic based on zirconia containing cerium and yttrium. Background technique

[0002] In recent years, zirconium dioxide (ZrO 2 )-based shape memory ceramics research and development are known: ZrO containing magnesium (Mg) 2 Shape memory ceramics, ZrO containing cerium (Ce) 2 Shape memory ceramics and ZrO containing yttrium (Y) 2 Binary ZrO such as shape memory ceramics 2 base shape memory ceramics. For ZrO 2 Based ceramics, which usually have high strength and toughness through stress-induced t→m martensitic transformation, and the above-mentioned added components can stabilize ZrO 2 Ceramic or crystal effect. The stress-induced martensitic phase exhibits the shape memory effect (SME) through reverse phase transformation by heating, that is, given a temperature change to the shape memory material, it can automatically work and recover its shape. For example, in ...

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