ISSN:
1662-0356
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Natural Sciences in General
,
Technology
Notes:
The degradation of electrical conductivity in porous nickel-yttria stabilized zirconiacomposite cermets in a H2/H2O atmosphere under high temperature treatments has beeninvestigated. The parameters varied were: temperature, water partial pressure, and electrical currentload. The microstructure was analyzed before and after the treatment by optical microscopy andfield emission scanning electron microscopy (FE-SEM). From the optical images the particle sizeand total amount of Ni, as area fraction, in the sample were measured. By the use of charge contrast(CC) in the FE-SEM particle size and area fraction of percolated Ni was measured. Temperatureproved to have the largest effect on the degradation. Samples tested at 1000°C, in contrast to 750°C,showed a severe decrease of conductivity and growth of Ni particles. Higher water partial pressureaccelerated Ni particle growth at both temperatures, but the loss of percolation and conductivity at1000°C was less severe under high water partial pressure. A possible explanation for this behavioris discussed
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/42/transtech_doi~10.4028%252Fwww.scientific.net%252FAST.45.1483.pdf
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