The shape recovery property of some glass ceramics and sintered ceramics has been investigated with high temperature torsion tests. 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. Sintered ceramics such as mica (KMg3AlSi3O10F2), silicon nitride (Si3N4), silicon carbide (SiC), zirconia (ZrO2) and alumina (Al2O3) showed similar phenomenon, indicating that the shape memory phenomenon of ceramics is not limited to glass ceramics generated by a special manufacturing process, but is found in material which contains little glass phase. A correspondence between the temperature range for shape memory and the stress relaxation temperature range was seen in all the materials studied. The critical prestrain, within which 100% shape recovery occurs, is about 0.1% with β-spodumene glass ceramics, silicon nitride and zirconia. This value is 1/5 that of mica glass ceramics.
|Number of pages||8|
|Journal||Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals|
|Publication status||Published - 1990 Jan|
ASJC Scopus subject areas
- Metals and Alloys