結晶化ガラスと焼結セラミックスの形状記憶現象

抄録

The shape recovery property of some glass-ceramics and sintered ceramics has been investigated with the high temperature range torsion test apparatus. The results are summarized as follows.
(1) The shape memory phenomena occurred in both β-spodumene glass-ceramics and 2ZnO-B₂O₃ glass-ceramics. This shows that the shape memory phenomenon of ceramics is not caused by the peculiar characteristics of mica crystal.
(2) The sintered ceramics such as mica (KMg₃AlSi₃O₁₀F₂), silicone nitride (Si₃N₄), silicone carbide (SiC), zirconia (ZrO₂) and alumina (Al₂O₃) brought the similar phenomenon, indicating that the shape memory phenomenon of ceramics is not limited to glass-ceramics generated by the special manufacturing process, but found in the material which contains little glass phase.
(3) The correspondence between the temperature range for the occurrence of shape memory phenomenon and the stress relaxation temperature range is recognized in all the materials studied in this paper.
(4) The critical prestrain, within which the 100% shape recovery occurs, is about 0.1% with β-spodumene glass-ceramics, silicone nitride and zirconia. This value is 1/5 that of mica glass-ceramics.