マグネシウム特集号 マグネシウム単結晶の｛１１２￣２｝〈１￣１￣２３〉すべり

Abstract

Magnesium single crystals were stretched in [1120] direction to investigate the deformation behavior by {1122} slip (SPCS). In a range from 77K to 133K, the yield stress decreases with increasing temperature, while the stress increases with increasing temperature in a range from 133K to 293K. The stress increases at all temperatures when strain rate is increased by a factor of a hundred. The deformation mode due to SPCS is investigated by observation of slip band. Narrow slip bands are formed at 77K just after yielding. The width of slip bands at yielding increases continuously with increasing temperature and coveres the whole specimen surface at 293K. The results of the observation by TEM show that double cross slip of (c+a) screw dislocations occurrs more frequently during deformation at 293K than at 77K. At 293K, there are scarcely (c+a) edge dislocations, while many c edge dislocations are observed in the crystals. The deformation mode and the deformation mechanism of magnesium by SPCS are similar to those of cadmium.