1 / 42

High Temperature Composites

High Temperature Composites. Rutgers University Federal Aviation Administration Advanced Materials Flammability Atlantic City, NJ October 24, 2001. Research Team. P. Balaguru J. Giancaspro C. Papakonstantinou R. Lyon (FAA). Introduction. Polysialate (“Geopolymer”) Aluminosilicate

warwickd
Download Presentation

High Temperature Composites

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. High Temperature Composites Rutgers University Federal Aviation Administration Advanced Materials Flammability Atlantic City, NJ October 24, 2001

  2. Research Team • P. Balaguru • J. Giancaspro • C. Papakonstantinou • R. Lyon (FAA)

  3. Introduction • Polysialate (“Geopolymer”) • Aluminosilicate • Water-based, non-toxic, durable • Resists temperatures up to 1000°C • Curing temperature: 20, 80, 150°C • Protects carbon from oxidation

  4. Ongoing Research at Rutgers • Mechanical properties of carbon and glass composites • Hybrid composites: carbon/glass and inorganic/organic • Structural sandwich panels • Comparison with other high temperature composites

  5. Hybrids: Fiber Characteristics • Glass – Economical, larger fiber diameter • Carbon – Higher modulus and strength, durability

  6. Variables • Eglass fiber core with carbon fiber skins • Number of layers on tension side: 1,2,3 • Type of carbon fabric: 1k and 3k woven, 3k unidirectional • Number of layers on the compression side: 1,2,3 • Specimen thickness: 6, 12, and 18 layers of glass fabrics

  7. Specimen Preparation • Hand impregnation • Room temperature (20°C) curing • 1 MPa of pressure for 24 hours • Post curing for 3 weeks • Room temp. curing reduces degradation of glass under alkali environment

  8. Test Setup • Simply supported • 3-point bending (ASTM D790) • Loading rate = 2.5 mm / min

  9. Mechanical Properties • Load – deflection response converted to stress and strain • Stress, • Strain,

  10. Assumptions for Analysis • Homogeneous • Elastic • Uncracked section • Perfect bond between glass and carbon layers

  11. Glass / Carbon Hybrid Results • Density • Failure pattern • Peak stress (strength) • Strain at peak load (ductility)

  12. Density • All glass: 2.36 g/cm3 • All carbon: 1.9 to 2.0 g/cm3 for 3 types • Increase in carbon layers provide consistent decrease in density

  13. Failure Pattern • Glass: brittle, no post-cracking strength • Glass with 1 and 2 carbon layers: failed in tension • Glass with 3 carbon layers: compression failure • Glass with both tension and compression reinforcement: compression failure

  14. 3k Unidirectional Carbon

  15. Samples with 2 Carbon Layers

  16. Varying Sample Thickness

  17. Maximum Stress: 3k Uni Carbon • Pure Glass: 103 MPa • Glass + 1 Layer: 212 MPa • Glass + 2 Layers: 379 MPa • Glass + 3 Layers: 354 MPa • 3k Unidirectional Carbon: 466 MPa

  18. Thickness vs. Maximum Stress • 6 Glass + 1 carbon (uni): 347 MPa • 12 Glass + 2 carbon : 379 MPa • 18 Glass + 3 carbon : 362 MPa

  19. Maximum Strains • Matrix (tension): 0.0007 • Matrix (compression): 0.005 • All Glass (tension): 0.003

  20. Maximum Strain: 3k Uni Carbon • Pure Glass: 0.003 • Glass + 1 Layer: 0.007 • Glass + 2 Layers: 0.011 • Glass + 3 Layers: 0.009 • 3k Uni Carbon: 0.005

  21. Thickness vs. Maximum Strain • 6 Glass + 1 carbon (uni): 0.012 • 12 Glass + 2 carbon : 0.011 • 18 Glass + 3 carbon : 0.011

  22. Conclusions: Glass/Carbon Hybrids • Eglass / carbon is a viable combination. • For all types of carbon fabric, 2 layers on the tension side provides the highest strength. • Placing carbon on both compression and tension faces does not significantly increase the strength.

  23. Conclusions: Glass/Carbon Hybrids • Eglass reinforced with 1, 2, or 3 carbon layers exhibited the highest strength when the fabric was 3k unidirectional • Slightly lower strengths were achieved using 3k woven carbon fabric • The lowest strengths were achieved using 1k woven carbon fabric

  24. Conclusions: Glass/Carbon Hybrids • The uncracked section modulus for Eglass reinforced with 1k or 3k woven on the tension side showed little change as the number of carbon layers increased. • 3k unidirectional carbon on the tension side provided a modulus increase with an increasing number of layers. • An increase in modulus also results for carbon on both compression and tension sides.

  25. Strain Capacity of Polysialates Cantilever Beam Method

  26. Variables Investigated • Silica / Alumina ratio • Discrete carbon fiber content • Effect of ceramic micro-fibers

  27. Influence of Carbon Fiber Content on Cracking Strain

  28. Effect of Microfibers Without Ceramic Microfibers With Ceramic Mircofibers

  29. Durability • Wet-Dry • Flexure • [±45°] In-Plane Shear • Thermo-mechanical • Exposure Temperatures (200, 400, 500, 600°C)

  30. Wet – Dry Durability

  31. Comparison of Polysialate and Other Inorganic Composites • Relative performance of polysialate composites • Processing requirements • Mechanical properties • Carbon/Carbon composites • Ceramic matrix composites • Carbon/Polysialate composites

  32. Stress vs. Strain Relationships of Bi-directional Composites in Tension

  33. Tensile Strength of Bi-directional Composites

  34. Flexural Strength of Unidirectional Composites

  35. Flexural Stress-Strain Relationships of Unidirectional Composites

  36. Flexural Strength of Bi-directional Composites

  37. Lightweight Sandwich Panels • Core features: • - Inorganic matrix + ceramic spheres • - Density: 0.6 to 0.7 g/cm3 • - Compressive strength: 5.12 MPa • Carbon fabric laminated onto facings

  38. Typical Section of Sandwich Slab (Panel) Lightweight ceramic core • Carbon facings on both tension and compression sides

  39. Flexural Strength of Slabs With Different Reinforcement

  40. Load vs. Deflection for Slabs

  41. Commercially available plates + Inorganic matrix layer • Glass plates • Carbon plates • Fatigue • Sandwich panels Future Research

More Related