West China Journal of Stomatology

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Influence on microstructure of dental zirconia ceramics prepared by two-step sintering

Jian Chao, Li Ning, Wu Zhikai, Teng Jing, Yan Jiazhen.   

  1. Functional Materials Laboratory, School of Manufacturing Science and Engineering, Sichuan University, Chengdu 610065, China
  • Received:2012-06-16 Revised:2013-04-22 Online:2013-10-01 Published:2013-10-01

Abstract:

Objective  To investigate the microstructure of dental zirconia ceramics prepared by two-step sintering. Methods  Nanostructured zirconia powder was dry compacted, cold isostatic pressed, and pre-sintered. The pre-sintered discs were cut processed into samples. Conventional sintering, single-step sintering, and two-step sintering were carried out, and density and grain size of the samples were measured. Afterward, T1 and/or T2 of two-step sintering ranges were measured. Effects on microstructure of different routes, which consisted of two-step sintering and conventional sintering were discussed. The influence of T1 and/or T2 on density and grain size were analyzed as well. Results  The range of T1 was between 1 450 ℃ and 1 550 ℃, and the range of T2 was between 1 250 ℃ and 1 350 ℃. Compared with conventional sintering, finer microstructure of higher density and smaller grain could be obtained by two-step sintering. Grain growth was dependent on T1, whereas density was not much related with T1. However, density was dependent on T2, and grain size was minimally influenced. Conclusion  Two-step sintering could ensure a sintering body with high density and small grain, which is good for optimizing the microstructure of dental zirconia ceramics.

Key words: zirconia, two-step sintering, grain, microstructure