Corrosion of Inorganic Non-Metallic Materials Ale

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Corrosion of Inorganic Non-Metallic Materials
Aleš HelebrantDepartment of Glass and Ceramics
ICT Prague, Czech Republicwww.usk.cz
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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

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Literature for further study

• McCauley 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., Jiricka A., Jiricková J. Corrosion
  of glass. Glass Sci. Tech. 77C, 85-94 (2004)
• Jiricka A. et al. Corrosion modeling of simple
  glasses from the systems SiO2-Na2O-CaO and
  SiO2-Na2O-MgO. Glass Sci.Tech. 76, 298-308 (2003)
• Jiricka 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

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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

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Structure of INM
cristobalite
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Structure of INM
K2O-SiO2 glass
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Structure of INM
silica glass
crystalline silica (quartz)
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Structure of INM
periclase MgO
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Structure of INM
zeolite
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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

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Dissolution
incongruent
congruent
t0
tgt0
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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?
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Models of congruent dissolution

• non-steady diffusion
• steady state diffusion
• surface reaction
• surface reaction and steady state diffusion

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Diffusion Ficks laws
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Non-steady diffusion
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Error function
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Non-steady diffusion
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Steady-state diffusion
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Steady-state diffusion
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Surface reaction
saturated conc. cs
conc. in bulk solution cl
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Surface reaction
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SR comparable with SD
cltcs
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SR comparable with SD
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Saturation effect