Composites

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A technical presentation on ceramic composites, advantages and uses. PPT also contains videos of ANSYS simulations of the same.

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Composites

  1. 1. A Technical Presentation on Ceramic Composites ByDESHPANDE JAYDEEP SANJEEV T.E. Mechanical PVG’S COET, PUNE. Under the guidance of Prof. P.G.Kulkarni
  2. 2. Contents: Introduction Monolithic vs. Composite Composites and applications Advantages Case Study
  3. 3. Introduction A ceramic is an inorganic, nonmetallic solid prepared by the action of heat and subsequent cooling. The word "ceramic" comes from the Greek word κεραμικός (keramikos), "of pottery" or "for pottery",from κέραμος (keramos), "potters clay, tile, pottery"
  4. 4. Introduction Base matrix + reinforcement = composite!
  5. 5. Composite -v- Monolithic Ceramics Interphase LOAD matrix fiber crack crack arrest Fiber Composite materials, whether platelet, choppedMatrix fiber, or continuous fiber reinforced are superior “engineering”materials to monolithics: • generally higher strength, especially in tension • much higher damage tolerance (fracture toughness)
  6. 6. Composite -v- Monolithic Ceramics 200 Carbon Fiber 150 Composite Strength (MPa) 100 Graphite 50 Toughness 0 MPa/m-1/2 0 0.2 0.4 0.6 0.8 1 Displacement (mm) Steel >50 Monolithic Ceramic 3 Monolithic CompositePlatelet Reinforced Ceramic 6 Strength (MPa) Strength (MPa) SiC 100 ± 50 220 ± 20 Chopped Fiber Reinforced 10Continuous Fiber Reinforced 25-30 Graphite 107 ± 20 176 ± 20 Ceramic
  7. 7. Why Composites
  8. 8. Advantages: Increased strength per unit volume Lesser weight Higher impact resistance Greater through thickness strength
  9. 9. Ceramic CompositesComposite Examples
  10. 10. Structural Composites in Aerospace Applications• Thermal protection system for a re-entry space vehicle: Nose corn, leading edge, …• Rocket engine: Extendable nozzle, aerospike engine, …• Scram-jet engine for a future space vehicle.
  11. 11. Exhaust Tail-cone Weaving / 2D Cloth + StitchingSuccessfully engine demonstrated at gas temperature 1573K (1998)
  12. 12. SiC/SiC Thrust chamber Weaving / 3-Axial BraidingSuccessfully hot firing tested at gas temperature 2073K (1998)
  13. 13. Short History of Materials10000 bc 5000 bc 0 1000 1500 1600 1900 1940 1960 1980 1990 2000 GOLD COPPER BRONZE IRON METALS CAST IRON POLYMERS/ STEELS ODS STEELS ELASTOMER WOOD LIGHT ALLOYS NEW SUPERALLOYS SKIN FIBERS GLUES SUPER ALLOYS GLASSY METALS RUBBER TITANIUM, COMPOSITES ZIRCONIUM etc. ALLOYS HIGH TEMPERATURE STRAW-BRICK HORSEHAIR POLYMERS PLASTER STONE HIGH MODULUS FLINT BAKELITE POLYMERS POTTERY NYLON POLYESTERS CERAMIC GLASS P.E. EPOXIES MATRIX METAL CEMENT PMMA ACRYLICS MATRIX REFRACTORIES CERAMICS/ PORTLAND C/C GLASSES GFRE CEMENT FUSED SILICA PYROLITIC TOUGHENED CERMETS CERAMICS CERAMICS 10000 bc 5000 bc 0 1000 1500 1600 1900 1940 1960 1980 1990 2000 Date
  14. 14. Yield Strength Strength of Various Materials Yield of Various Structural Materials 600 500 Superalloy C/C Composite Ceramic Composites 400Yield Strength (MPa) SiC/SiC 300 Carbon Ste e l Zircaloy 200 Stainle ss Ste e l 100 Graphite 0 0.0 400.0 800.0 1200.0 1600.0 Temperature (°C)
  15. 15. CERAMIC COMPOSITES Latest and the most advanced material in the market Provide very high strength Reduce weight greatly Better impact properties Higher in plane properties Very high operating temperatures
  16. 16. CASE STUDY
  17. 17. Impact on 12mm steel plate Muzzle Velocity=500m/s
  18. 18. Case Study: Ballistic Impact Ceramic tiles are a good replacement for steel armor plates Weight Strength
  19. 19. Impact on ceramic tile Muzzle velocity =1200m/s
  20. 20. Impact Characteristics Monolithic ceramic tiles crumble under impact loading In plane properties are weak Yet impact resistance is good because of the failure mechanism of ceramic
  21. 21. Failure Mechanism Under high energy impact ceramic material fails, forming fine ceramic dust This dust is confined by surrounding ceramic structure Thus it provides no route for failed material to escape As a result penetrating projectile faces great resistance and loses out energy
  22. 22. Failure of monolithic ceramic Muzzle velocity =1200m/s
  23. 23. Failure of monolithic ceramic Muzzle velocity =1200m/s
  24. 24. Monolithic Ceramic: Problem During the course of impact, layers of the ceramic stacking move parallel to each other due to inter-laminar shear stress This causes delamination of the monolithic crystal Also monolithic crystal allows for easy through thickness crack propagation
  25. 25. Effects of reinforcement Reinforcement in the monolithic ceramic tile improves ILSS properties It prevents delamination to some extent Through thickness crack propagation is reduced Reinforcing fibres take the impact loading and prevent the matrix from cracking Fibres help in holding the matrix together
  26. 26. SiC Whisker Reinforced Ceramic Tiles
  27. 27. Popular reinforcements Glass fibre Carbon fibre Silicon carbide Kevlar™
  28. 28. Popular Matrix Materials Alumina Zirconia Zirconia toughened Alumina (ZTA) Cr3C2 CeO2 TiN
  29. 29. Conclusion Thus wherever weight constraints hinder the use of thick steel plates, Ceramic composites provide the best solution. In defense applications ceramic composite tiles are popularly used in ballistic impact protection tiles and vests. Ceramic composites are also popularly used in high temperature applications such as rocket nozzles and reactors.

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