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Ageing Behavior of Injection-Molded ZTA Ceramics as a Function of Stabilizer Content
M. Abou el Ezz1, F. Kern2, R. Gadow2
1 Graduate School of Excellence for Advanced Manufacturing Engineering, Stuttgart University, Institute for Manufacturing Technologies of Ceramic Components and Composites, Allmandring 7 b, D-70569, Germany
2 Stuttgart University, Institute for Manufacturing Technologies of Ceramic Components and Composites, Allmandring 7 b, D-70569, Germany
received July 13, 2011, received in revised form September 19, 2011, accepted October 21, 2011
Vol. 2, No. 4, Pages 191-196 DOI: 10.4416/JCST2011-00025
Abstract
ZTA (zirconia-toughened alumina) ceramics are interesting materials for biomedical implants. High-quality implants are currently produced by means of cold isostatic pressing. The production of ZTA ceramic components by injection molding enables their mass production and an improvement in the cost and quality of complex near-net-shaped ceramic components. Injection-molded and hot-pressed ZTA materials with 10 vol% zirconia stabilized with 0, 1.5 and 3 mol% yttria were prepared and aged in an autoclave in water vapor at 134 °C for up to 48 h, corresponding to ∼ 175 years in vivo. The phase compositions of the aged samples were examined by means of X-ray diffraction. In both experiments, it was shown that the ageing resistance of ZTA materials rises significantly with increasing stabilizer content. Compared to injection-molded and pressureless-sintered materials, fully dense hot-pressed ZTAs have shown improved long-term ageing stability. The ageing behavior of ZTA is obviously dependent on the forming process, relative density and yttria content.
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Keywords
ZTA, ceramic injection molding, ageing behavior, mechanical properties
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