Corrosion of Inorganic NonMetallic Materials Ale Helebrant Department

Corrosion of Inorganic Non-Metallic Materials Aleš Helebrant Department of Glass and Ceramics ICT Prague, Czech Republic www. usk. cz Corrosion of Materials Course

Contents • Inorganic Non-Metallic Materials • Principles of INM corrosion, congruent and incongruent dissolution • Control mechanisms of dissolution, mathematical description • Corrosion of ceramics • Corrosion of glass • Enamels as surface layers on metals • Corrosion of concrete – Typical examples of materials – Corrosion mechanisms – Increasing chemical durability Corrosion of Materials Course

Literature for further study • • Mc. Cauley R. A. : Corrosion of Ceramics. Marcel Dekker, Inc. New York 1995 Clark D. E. , Zoitos B. K. (eds. ): Corrosion of Glass, Ceramics and Ceramic Superconductors. Noyes Publications, Park Ridge, New Jersey, 1992 Doremus, R. H. : Chemical durability of glass. In: Tomozawa, M; , Doremus, R. H. (eds. ): Treatise on Materials Science and Technology 17, Academic Press 1979, pp. 41 -67 Helebrant A. : Kinetics of corrosion of silicate glasses in aqueous solutions. Ceramics-Silikáty 41, 147 -151 (1997) Helebrant A. , Jiřička A. , Jiřičková J. : Corrosion of glass. Glass Sci. Tech. 77 C, 8594 (2004) Jiřička A. et al. : Corrosion modeling of simple glasses from the systems Si. O 2 -Na 2 O -Ca. O and Si. O 2 -Na 2 O-Mg. O. Glass Sci. Tech. 76, 298 -308 (2003) Jiřička A. , Helebrant A. : Dissolution of soda-lime, silica and high-level waste glass by single-pass flow-through and static tests. In: Environmental Issues and Waste Management Technologies in the Ceramic and Nuclear Industries V (Ceramic Transactions, Vol 107, eds. Chandler G. T. , Feng X. ), The American Ceramic Society, Westerville, OH, USA, 2000, pp. 309 -316 Corrosion of Materials Course

Inorganic Non-metallic Materials • INM – – – Ceramics Glass Inorganic binders (cement, gypsum) Monocrystals Glass-ceramics – Inorganic Non-Metallic Materials = Ceramics (US) – Ceramics (UK) = pottery, construction ceramics, porcelain, refractories. . . • Traditional INM – based on silicates or silica Corrosion of Materials Course

Structure of INM cristobalite Corrosion of Materials Course

Structure of INM K 2 O-Si. O 2 glass Corrosion of Materials Course

Structure of INM silica glass crystalline silica (quartz) Corrosion of Materials Course

Structure of INM periclase Mg. O Corrosion of Materials Course

Structure of INM zeolite Corrosion of Materials Course

Corrosion of INM • corrosion of metals – electrochemical process • corrosion of INM – dissolution – reaction with liquids (aqueous solutions, melts) – reaction with gasses • sometimes connected with subsequent degradation Corrosion of Materials Course

Dissolution congruent incongruent t=0 t>0 Corrosion of Materials Course

Congruent dissolution solidus liquidus 1) surface reaction 2) transport of surface reaction products into the solution bulk (diffusion) Which process controls the overal rate of dissolution? Corrosion of Materials Course

Models of congruent dissolution • • non-steady diffusion steady state diffusion surface reaction and steady state diffusion Corrosion of Materials Course

Diffusion – Fick‘s laws Corrosion of Materials Course

Non-steady diffusion saturated conc cs conc. in bulk solution cl Corrosion of Materials Course

Error function Corrosion of Materials Course

Non-steady diffusion Corrosion of Materials Course

Steady-state diffusion saturated conc. cs conc. in bulk solution cl h Corrosion of Materials Course

Steady-state diffusion Corrosion of Materials Course

Surface reaction saturated conc. cs conc. in bulk solution cl Corrosion of Materials Course

Surface reaction Corrosion of Materials Course

SR comparable with SD saturated conc. cs c‘<cs conc. in bulk solution cl h Corrosion of Materials Course

SR comparable with SD Corrosion of Materials Course

Saturation effect Corrosion of Materials Course