Ion Implantation으로 Ca를 첨가된 단결정 $Al_2$O$_3$의 Crack-Like Pore의 Healing 거동-III: Stability of Crack-Like Pore = Effects of Ca Implantation on the Sintering and Crack Healing Behavior of High Purity $Al_2$O$_3$ Using Micro-Lithographic Technique-III: Stability of Crack-Like Pore

다국어 초록 (Multilingual Abstract)

The inner crack-like pore with controlled amount of Ca impurity in the high purity alumina single crystal sapphire had been created by micro-fabrication technique which includes ion implanation photo-lithography Ar ion milling and hot press technique. The crack-like pores in two-hour hot pressed specimen were extremely stable even after heat treating at 1,80$0^{\circ}C$ for 5 hours almost no healing was observed. But the crack-like pores in one-hour hot pressed specimen at 1,30$0^{\circ}C$ were healed by heat treatment and the amount of healing was increased with the heat treatment time and temperature and the amount of Ca addition. The edges of crack-like pore parallel to <1100> direction in (001) basal plane were stable but the edges normal to this direction in (00101) plane <1120> direction were unstable to facetting This means that the surface energy of alumina along the <1100> direction in (0001) basal plane in much lower than <1120> direction.