MTL200 Theory

• Ceramics


  Inorganic, nonmetallic materials that are formed by the application of heat
• Ceramics


  • Typically have high melting temperatures
  • Are hard and brittle
  • Are poor conductors of electricity and heat
• Types of ceramic materials

  • Glasses
  • Glass-ceramics
  • Structural clay products
  • Whitewares
  • Refractories
  • Abrasives
  • Cements
  • Ceramic biomaterials
  • Carbons
  • Advanced ceramics
• Ceramics


  Normally cannot be fabricated using conventional metal-forming techniques, often formed using powder compaction methods and subsequently fired (heat-treated)
• Glasses


  Noncrystalline silicates containing other oxides like CaO, Na2O, K2O, and Al2O3 which influence the glass properties
• Typical soda-lime glass consists of approximately 70 wt% SiO2, the balance being mainly Na2O (soda) and CaO (lime)
• Glasses


  • Have optical transparency
  • Relatively easy to fabricate
• Glass-ceramics


  Crystalline materials formed by the proper high-temperature heat treatment of glasses, involving nucleation and growth stages
• A nucleating agent (frequently titanium dioxide) is often added to the glass to promote crystallization
• Glass-ceramics


  • Have relatively high mechanical strengths
  • Have low coefficients of thermal expansion (to avoid thermal shock)
  • Have good high-temperature capabilities
  • Have good dielectric properties
  • Have good biological compatibility
  • Can be made optically transparent or opaque
  • Can be fabricated using conventional glass-forming techniques