• A ceramic material may be defined as any inorganic crystalline material,compounded of a metal and a non-metal .• Ceramics can be classified as Crystalline ceramics & Non-crystallineceramics .• Crystalline ceramic materials are not amenable to a great range ofprocessing.• Non-crystalline ceramics, being glasses, tend to be formed from melts. Theglass is shaped when it is fully molten .
Glass-ceramic• Glass-ceramic materials share many properties with both glasses andceramics.• Glass-ceramics have the fabrication advantage of glass as well as specialproperties of ceramics.• Glass-ceramics usually have between 30% [m/m] to 90% [m/m]crystallinity• Glass-ceramics have many interesting properties like zero porosity, highstrength, toughness• low or even negative thermal expansion, high temperature stability .
Advanced ceramics VS Traditional ceramics• large numbers of materials are ceramics.• The applications for these materials are diverse, from bricks and tiles toelectronic and magnetic components.• The functions of ceramic products are dependent on their chemicalcomposition and microstructure , which determines their properties.• traditional clay-based ceramics have been used forover 25,000 years,advanced ceramics have generally been developed within the last 100years
• Traditional ceramics are usually based on clay and silica.• traditional ceramics mainly used with low technology applications .• Advanced ceramics are also referred to as “special,”“technical,” or“engineering” ceramics.• advanced ceramics have superior mechanical properties• corrosion resistance• electrical & optical properties.• magnetic properties.
Advanced ceramics applications• Automotive• Electronic applications• Energy and enviroment• Mechanical engineering• Medical technology• Aerospace• Modern industries
Advanced Ceramics in the Automotive Industry• In engines heat-resistant ceramic parts like valve components• backings in the crankshaft housing and components for water and fuelpumps• To increased efficiency, less wear and lower noise emission.
Advanced Ceramics in Equipment andMechanical Engineering• high wear resistance, temperature resistance and a high level of corrosionresistance• make ceramics safe than other materials in equipment & mechanical use .• cutting tools , mechanical pumps
Advanced Ceramics in Electronics• ceramic heat-sinks provide the right climate for high-power electronics.• Capacitors• Insulators
Advanced Ceramics in Medical Technology• Biocompatible and wear-resistant advanced ceramics enable doctors toprovide patients with optimum care and help patients master thechallenges of everyday life again.• Artificial bone• dental products
Advanced Ceramics in Energy and Environment• Ceramic materials enable safe, low-wear process control .• reduce emissions and ensure efficient use of resources in many areas ofenergy supply and environmental technology.
• in the field of environmental technology – for instance in water treatmentor recycling and processing and recycling of waste• ceramic components ensure long life for parts that are subject to highstress during conveying, transport or the processing of raw materials,minerals and resources• Ceramic materials can withstand extreme temperatures and mechanicalstresses in applications for generating energy in power plant engines andturbines or in systems for photovoltaics , solar thermal energy conversion,wind and water power.
Aerospace• Engines ; Shielding a hot running airplane engine from damaging othercomponents.• Airframes ; Used as a high-stress, high-temp and lightweight bearing andstructural component.• Missile nose-cones ; Shielding the missile internalsfrom heat.• Space Shuttle tiles .• Rocket nozzles, withstands and focuses the exhaust of the rocket booster.
Modern industry• Zirconium dioxide ceramics are used in the manufacture of knives. Theblade of the ceramic knife will stay sharp for much longer than that of asteel knife• Ceramics such as alumina, boron carbide and silicon carbide have beenused in bulletproof vests• Silicon nitride parts are used in ceramic ball bearings. Their higherhardness means that they are much less susceptible to wear and can offermore than triple lifetimes.• High-tech ceramic is used in watchmaking for producing watch cases. Thematerial is valued by watchmakers for its light weight, scratch-resistance,durability and smooth touch.