사파이어 단결정의 basal (0001) 결정면에 미세압흔시 온도에 따른 압흔 주위 미세구조에 관한 연구

윤석영; Seog-Young Yoon

Korean Journal of Materials Research, Vol.10, No.11, 784-792, November, 2000

The Substructure Near Indents With Temperature During Microindentation on Basal (0001) Plane in Sapphire Single Crystals

윤석영

부산대학교 공과대학 무기재료공학과

Seog-Young Yoon

Dept. of Inorganic Materials Engineering, Pusan National University, 30, Changjung-Dong, Kumjung-Gu, Pusan 609-735, Korea

The Vickers microhardness was measured on the basal (0001) plane of sapphire single crystals in the temperature range from 25 ? C to 1000 ? C . The substructure surrounding the indents was investigated using selective chemical polishing and etching, optical microscopy, and trasmission electron microscopy (TEM). At room temperature, cracks were predominant, and at intermediate temperatures (400 ? C and 600 ? C ), extensive rhombohedral twinning was observed. On the other hand, at higher temperatures, prism plane slip bands on prism plane {1120}(원문참조) were dominant in the microstructure. TEM observations revealed that the dislocation substructure at the vicinity of the indents consisted of fairly straight dislocations lying in basal and/or prism planes and aligned along the and directions. The details of the glide dissociation of perfect screw dislocations into three collinear 1/3 partials on the prism plane and the Peierls potential for sapphire single crystals were discussed.

Keywords:Sapphire Single;crystals;etching;Microindentation

[References]

Mitchell TE, Lagerlf KPD, Heuer AH, Mater. Sci. Technol., 1, 349 (1985)
Cadoz J, Castaing J, Kirby SH, J. Am. Ceram. Soc., 64, 504 (1981)
Kronberg ML, J. Am. Ceram. Soc., 45(6), 274 (1962)
Conrad H, Stone G, Janowski K, Trans. AIME, 233(5), 889 (1965)
Chang R, J. Appl. Phys., 31(3), 484 (1960)
Becher PF, J. Am. Ceram. Soc., 59(1), 59 (1976)
Kronberg ML, Acta. Metall., 5(9), 507 (1957)
Gooch DJ, Groves GW, Acta. Metall., 55(2), 105 (1972)
Snow JD, Heuer AH, J. Am. Ceram. Soc., 56(3), 153 (1973)
Pletka BJ, Heuer AH, Mitchell TE, Acta. Metall., 25, 25 (1977)
Pletka BJ, Mitchell TE, Heuer AH, J. Am. Ceram. Soc., 57(9), 388 (1974)
Chan HM, Lawn BR, J. Am. Ceram. Soc., 71(1), 29 (1988)
Kollenberg W, J. Mater. Sci., 23 (1988)
Hirth JP, Lothe J, Theory of Dislocations/ McGraw-Hill, 1982 (1982)
Lagerl KPD, Heuer AH, Castaing J, Riviere JP, Mitchell TE, J. Am. Ceram. Soc., 77(2), 385 (1994)

[Related Articles]

[1] Mitchell TE, Lagerlf KPD, Heuer AH, Mater. Sci. Technol., 1, 349 (1985)

[2] Cadoz J, Castaing J, Kirby SH, J. Am. Ceram. Soc., 64, 504 (1981)

[3] Kronberg ML, J. Am. Ceram. Soc., 45(6), 274 (1962)

[4] Conrad H, Stone G, Janowski K, Trans. AIME, 233(5), 889 (1965)

[5] Chang R, J. Appl. Phys., 31(3), 484 (1960)

[6] Becher PF, J. Am. Ceram. Soc., 59(1), 59 (1976)

[7] Kronberg ML, Acta. Metall., 5(9), 507 (1957)

[8] Gooch DJ, Groves GW, Acta. Metall., 55(2), 105 (1972)

[9] Snow JD, Heuer AH, J. Am. Ceram. Soc., 56(3), 153 (1973)

[10] Pletka BJ, Heuer AH, Mitchell TE, Acta. Metall., 25, 25 (1977)

[11] Pletka BJ, Mitchell TE, Heuer AH, J. Am. Ceram. Soc., 57(9), 388 (1974)

[12] Chan HM, Lawn BR, J. Am. Ceram. Soc., 71(1), 29 (1988)

[13] Kollenberg W, J. Mater. Sci., 23 (1988)

[14] Hirth JP, Lothe J, Theory of Dislocations/ McGraw-Hill, 1982 (1982)

[15] Lagerl KPD, Heuer AH, Castaing J, Riviere JP, Mitchell TE, J. Am. Ceram. Soc., 77(2), 385 (1994)