Corrosion penetration monitoring of advanced ceramics in hot aqueous fluids

Materials Research

Klaus G. Nickel¹  Björn Seipel¹ 

[1] ,University Tübingen Institute for Geosciences Applied Mineralogy Wilhelmstr,Germany

关键词: Ceramics;    nitrides;    aqueous;    corrosion;    penetration monitoring;   

DOI  :  10.1590/S1516-14392004000100017

来源: SciELO

【 摘 要 】

Advanced ceramics are considered as components in energy related systems, because they are known to be strong, wear and corrosion resistant in many environments, even at temperatures well exceeding 1000 °C. However, the presence of additives or impurities in important ceramics, for example those based on Silicon Nitride (Si3N4) or Al2O3 makes them vulnerable to the corrosion by hot aqueous fluids. The temperatures in this type of corrosion range from several tens of centigrade to hydrothermal conditions above 100 °C. The corrosion processes in such media depend on both pH and temperature and include often partial leaching of the ceramics, which cannot be monitored easily by classical gravimetric or electrochemical methods. Successful corrosion penetration depth monitoring by polarized reflected light optical microscopy (color changes), Micro Raman Spectroscopy (luminescence changes) and SEM (porosity changes) will be outlined. The corrosion process and its kinetics are monitored best by microanalysis of cross sections, Raman spectroscopy and eluate chemistry changes in addition to mass changes. Direct cross-calibrations between corrosion penetration and mechanical strength is only possible for severe corrosion. The methods outlined should be applicable to any ceramics corrosion process with partial leaching by fluids, melts or slags.

【 授权许可】

CC BY   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License