ISSN:
1662-0356
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Natural Sciences in General
,
Technology
Notes:
The superplastic flow in tetragonal zirconia polycrystals stabilised 3mol% Y2O3 (3YTZP)is strongly affected by the dopant cations, which segregate at the grain boundary. It isproposed that this flow is controlled by grain boundary diffusion of Zr4+ ions and therefore thedopant cations should change the grain boundary diffusion. In order to prove this thesis themeasurements of grain boundary diffusion coefficients were made using Hf4+ ions as tracer.Zirconia samples were doped with 1mol% of Al2O3, SiO2, MgO, MgAl2O4, GeO2 and TiO2. Thetracer was deposited on the surface of the zirconia specimens by placing several drops of hafniumnitrate and then drying at 373 K. In this way, thin films of HfO 2 were obtained. The samples wereheated in the range 1553 – 1773 K for 1 to 24 h. The concentration versus depth profiles weremeasured using secondary ion mass spectrometry (SIMS). Calculated hence grain boundarydiffusion coefficients were several times bigger for doped samples than for pure 3Y-TZP samples
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/42/transtech_doi~10.4028%252Fwww.scientific.net%252FAST.45.1626.pdf
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