1. CHARACTERISTICS OF CERAMIC MATERIALS Chapter 12

2. Ceramic products made out of clay, an inorganic, nonmetallic solid material that if derived from naturally decomposed granite Consists of, Kaolinite – aluminum oxide, quartz and water Clay and glass are the two major ceramics industries Products like brick, pottery and artware made from sand and clay for centuries Still manufactured using similar methods Advanced ceramics of today: High temp cutting tools Body armor Artificial joints Etc.

3. Unique Characteristics of Ceramics Advantages High melting temps High hardness High modulus of elasticity High compressive strength Low electrical and thermal conductivity Advantages over metallic parts Better wear resistance Greater strength at high temps Resistance to harsh chemicals Made with high range of densities

4. Disadvantages Less tough than metals and some composites Low impact strength Brittle fatigue Brittleness can be engineered out of ceramics Ceramic matrix composites Reinforcing fibers Apply ceramic coating to metal substrates Fatigue reduced by compacting the powder

5. Applications of Ceramics Space Ceramic tiles cover the underside of the space shuttle Insulates to temperatures approaching 3,000°F Military NATO C-130 transport aircraft - aramid fiber and glass ceramic cockpit armor Ceramics used to line gun barrels Armor Ammunition parts Medical fields Nearly Inert – devices implanted in the body without causing toxic reactions Surface-active – form a chemical bond with the surrounding tissue and encourage growth Resorbable – materials that dissolve into the blood stream

6. Hip and knee joints Ceramic heart valves Dental implants Coatings on surgical instruments Automotive Spark plug insulators Catalytic converters Oxygen sensors Computer control systems Magnets Brake rotors Ceramic engine block is being developed (difficult to machine and lubricate)

7. Construction (residential and commercial) Floor tile Brick Roofing Cement Sewer pipe Glass 3 billion square feet of glass used per year on windows Enough glass to build a 200 foot wide highway from Los Angeles to New York Hazardous material Containment Used to encapsulate hazardous materials Can be mixed with clay (rendered harmless) and made into consumer products

8. Materials for Ceramics Silicates and aluminum silicates Plentiful Clay Kaolin Sand Feldspar Carbonate Soapstone

9. The Ceramics Industry Firms are classified by the type of products they manufacture 2 major sectors

10. Traditional Ceramics Generally concerned with the production of glass and clay products Potteries and glassmaking Also includes concrete and sandpaper 6 major segments: Structural clay products Whiteware Refractories Glass Abrasives Cement

11. Advanced Ceramics Also called Industrial Ceramics and Structural Ceramics Manufacture products from engineered materials (human-made) Meet the needs of unique and highly specialized environments 4 major segments: Structural Electrical Coatings Chemical and environmental ceramics Products from sports medicine to communication satellites

12. Nature of Industrial Stock Clay usually purchased as a dry powder, or semidry, plastic state Powders can be compressed producing dense durable parts Green body (green compact, greenware) – a fragile part that has not been fired in an oven Still fragile Easier to machine (green machining) Good for parts with complex geometry

13. Liquid or semiliquid clay Injection molding and extrusion processes Glass manufacturers purchase stock in beads or sheets

14. Report Choose 2 of the following: Brake pads Knives Cookware Bearings Advantages/disadvantages Compare to other materials these products are made out of List sources of information