Spark Plasma Sintering of Alumina

Journal of the American Ceramic Society - Tập 85 Số 8 - Trang 1921-1927 - 2002
Zhijian Shen1, Mats Johnsson1, Zhe Zhao1, Mats Nygren1
1Department of Inorganic Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91, Stockholm, Sweden

Tóm tắt

A systematic study of various spark plasma sintering (SPS) parameters, namely temperature, holding time, heating rate, pressure, and pulse sequence, was conducted to investigate their effect on the densification, grain‐growth kinetics, hardness, and fracture toughness of a commercially available submicrometer‐sized Al2O3 powder. The obtained experimental data clearly show that the SPS process enhances both densification and grain growth. Thus, Al2O3 could be fully densified at a much lower temperature (1150°C), within a much shorter time (minutes), than in more conventional sintering processes. It is suggested that the densification is enhanced in the initial part of the sintering cycle by a local spark‐discharge process in the vicinity of contacting particles, and that both grain‐boundary diffusion and grain‐boundary migration are enhanced by the electrical field originating from the pulsed direct current used for heating the sample. Both the diffusion and the migration that promote the grain growth were found to be strongly dependent on temperature, implying that it is possible to retain the original fine‐grained structure in fully densified bodies by avoiding a too high sintering temperature. Hardness values in the range 21–22 GPa and fracture toughness values of 3.5 ± 0.5 MPa·m1/2 were found for the compacts containing submicrometer‐sized Al2O3 grains.

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Tài liệu tham khảo

10.4164/sptj.30.11_790

10.1111/j.1151-2916.1999.tb01874.x

10.1557/JMR.1995.0237

10.1557/JMR.1998.0013

10.1016/S0921-5093(00)00772-3

10.2497/jjspm.46.816

10.1016/S0955-2219(00)00086-8

10.1557/JMR.2000.0140

10.1111/j.1151-2916.2000.tb01380.x

10.1111/j.1151-2916.1969.tb11975.x

10.1111/j.1151-2916.1981.tb10320.x

10.1111/j.1151-2916.1984.tb19491.x

10.1111/j.1151-2916.1988.tb07533.x

10.1016/0955-2219(96)00044-1

10.1111/j.1151-2916.1989.tb05945.x

10.1111/j.1151-2916.1997.tb03208.x

10.1016/S0955-2219(01)00510-6

Munir Z. A., 1993, The Effect of External Fields on Mass‐Transpon and Defect‐Related Phenomena, J. Mater. Synth. Process., 1, 3

10.1016/S0167-577X(99)00289-X

10.1111/j.1151-2916.1995.tb08508.x

10.1111/j.1151-2916.1995.tb08452.x

10.1016/0921-5093(95)10155-1

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Journal of the American Ceramic Society

Tập 85 Số 8

1921-1927

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