리늄판의 미세경도 온도 및 응력의존성

윤석영; K.P.D. Lagerlof; Seog-Young Yoon; K.P.D. Lagerlof

Korean Journal of Materials Research, Vol.10, No.5, 335-342, May, 2000

Export Citation

리늄판의 미세경도 온도 및 응력의존성

Temperature and Dependence of the Microhardness of Rhenium Sheets

윤석영 , K.P.D. Lagerlof¹

부산대학교 무기재료공학과
¹CWRU 재료공학과

Seog-Young Yoon , and K.P.D. Lagerlof¹

Dept. of Inorganic Materials Engineering, Pusan National University, 30, Changjung-Dong, Kumjung-Gu, Pusan 609-735, Korea
¹Associate professor, Department of Materials Science and Engineering, Case Western Reserve University, Cleveland, OH 44106 USA

초록

리늄판의 미세경도를 압흔 하중 및 온도의 함수로 구하였다. 미세경도의 온도의존성은 상온에서 100 0 ? C 까지의 범위에서 Vickers 압흔기가 내장된 고온 미세압흔기를 이용하여 연구되었다. 미세경도의 하중의존성은 Vickers와 Knoop 압흔기를 이용하여 검토되었다. 압흔 크기 영향은 표준화된 Meyers법칙에 위해 충분히 설명 되었다. 압흔도중 압흔기 아래에서의 가공경화 때문에 어닐링된 리늄판 경도값은 높은 압흔 하중에서 압련되 리늄판의 경도값에 접근하였다. 경도의 하중의존성으로부터 외삽하여 얻어진 하중 영에서의 경도값은 경도값이 다른 열활성을 나타내는 두 개의 다른 기구에 의해 제어됨을 제시하였다. 낮은 온도에서 활성화에너지는 0.02eV 였으며, 한편 높은 온도에서 활성화에너지는 0.15eV 였다. 이때 전이온도는 대략 250 ? C 이었다.

The microhardness of rhenium sheets was determined as a function of indentation load and temperature. The temperature dependence of the microhardness between room temperatures and 1000 ? C was studied using a hot microhardness tester equipped with a Vickers indenter. The load dependence of the microhardness was investigated using oth a Vickers and a Knoop indenter. The indentation size effect (ISE) was well explained using the normalized Meyers law. The hardness of the annealed rhenium sheet approached that of the as-rolled sheets at large indentation loads because of work-hardening under the indenter during indentation. The hardness at zero load(obtained from extrapolation of the load dependence of the hardness) suggested that the hardness is controlled by two different mech-anisms having different thermal activation. At low temperature the activation energy for the mechanism controlling the hardness was approximately 0.02 eV , Whereas at higher temperatures that was approximately 0.15eV. The tranisi-tion temperature between the two different controlling mechanisms was about 250 ? C.

Keywords:cold working;hardness testing;mechanical propperties

[References]

Bryskin BD, Advanced Materials and Processes/ 1992 (1992)
Bryskin BD, ElGenk MS(ed.), Hoover MD(ed.), Proceedings of the Ninth Symposium on Space Nuclear Power Systems, 278 (1992)
Hamilton JC, Yang NYC, Clift WM, Boehme DR, McCarty KF, Franklin JE, Met. Trans., 23A, 851 (1992)
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Li H, Ghsh A, Han YH, Bradt RC, J. Mater. Res., 8(5), 1028 (1993)
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Li H, Bradt RC, J. Non-crystalline. Solids., 146, 197 (1992)
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Gane N, Cox JM, Philos. Mag., 22, 881 (1970)
Meyer E, Phys. Z., 9, 66 (1980)
LI H, Bradt RC, A142, 51 (1991). (1991)
Pollock HM, Daugis D, Maruins M, in Microindentation Tecnoniques in Materials Science and Engineering, edited Blau PJ, Lawn BR, ASTM STP 889 (ASTM, Philadephia, PA, 1984). (1984)
Li S, Ghosh A, Kobayashi AS, Bradt RC, J. Am. Ceram. Soc., 72, 904 (1989)

[Related Articles]

[1] Bryskin BD, Advanced Materials and Processes/ 1992 (1992)

[2] Bryskin BD, ElGenk MS(ed.), Hoover MD(ed.), Proceedings of the Ninth Symposium on Space Nuclear Power Systems, 278 (1992)

[3] Hamilton JC, Yang NYC, Clift WM, Boehme DR, McCarty KF, Franklin JE, Met. Trans., 23A, 851 (1992)

[4] Savitski EM, Tylkina MA, Povarova KB, Israel Program for Scientific Translations, 33 (1970)

[5] Carlen JC, Bryskin B, International J.of Refr. Met. Hard Mater., 11(6), 343 (1992)

[6] Larikov L, Belyakova M, Rafalovski V, Cryst. Res. Technol., 26(2), 239 (1991)

[7] Li H, Ghsh A, Han YH, Bradt RC, J. Mater. Res., 8(5), 1028 (1993)

[8] Li H, Bradt RC, J. Mater. Sci., 28, 917 (1993)

[9] Li H, Bradt RC, J. Non-crystalline. Solids., 146, 197 (1992)

[10] Standard Test Methods for Microhardness of Materials, Annual Book of ASTM Standards/ v.E384, pp.497-518, 1984 (1984)

[11] Gane N, Cox JM, Philos. Mag., 22, 881 (1970)

[12] Meyer E, Phys. Z., 9, 66 (1980)

[13] LI H, Bradt RC, A142, 51 (1991). (1991)

[14] Pollock HM, Daugis D, Maruins M, in Microindentation Tecnoniques in Materials Science and Engineering, edited Blau PJ, Lawn BR, ASTM STP 889 (ASTM, Philadephia, PA, 1984). (1984)

[15] Li S, Ghosh A, Kobayashi AS, Bradt RC, J. Am. Ceram. Soc., 72, 904 (1989)