사파이어 ($alpha$-$Al_2$$O_3$) 단결정에 있어 basal slip (0001)1/3<1120>의 전위속도를 4점 곡강도를 이용하여, 측정하였다. 이 곡강도는 온도 $1200^{circ}C$ 에서 $1400^{circ}C$ 그리고 응력은 90MPa, 120MPa, 160MPa에서 행하여졌다. 전위속도는 4 점굽힘 시편의 굽힘변위속도에 의해 구하여졌다. 얻어진 전위속도를 이용하여 전위속도의 온도 및 응력 의존성에 대해 검토하였다. 전위속도의 온도의존성을 이용하여 basal slip 전위속도를 위한 활성화에너지를 구하였으며, 그 값은 대략 2.2$pm$0.4eV이었다. 한편, 전위속도의 응력의존성을 나타내는 응력지수 m은 2.0$pm$0.2이었다.
The basal slip (0001)1/3<1120 > dislocation velocity in sapphire ($alpha$-$Al_2$$O_3$) single crystals was measured by four-point bending test. The bending experiment was carried out in the temperature range from 120$0^{circ}C$ to $1400^{circ}C$ at various engineering stresses 90MPa, 120MPa, and 150MPa. The velocity of such dislocations was estimated from the bending displacement rate of the four-point bend sample. The dependence of temperature and stress in dislocation velocity was investigated. The activation energy for dislocation velocity was determined to be about 2.2$pm$0.4eV. In addition, the stress exponent (m) describing the stress dependence of dislocation velocities was in the range of 2.0$pm$0.2.
