1. Composites - overview Artificial combination of matrix phase & dispersed phase Artificial combination of matrix phase & dispersed phase Matrix: metal, alloy ceramic mat'l polymer Matrix: metal, alloy ceramic mat'l polymer Dispersed phase: particulate fiber Dispersed phase: particulate fiber

2. Composites - metal matrix composites (MMCs) Particulates: ThO 2 -dispersed Ni (TD Ni) sintered Al powder (SAP) Particulates: ThO 2 -dispersed Ni (TD Ni) sintered Al powder (SAP) - except strengthening maintained at hi T Improves: strength creep resistance hi T corrosion resistance Improves: strength creep resistance hi T corrosion resistance Works like precipitation hardening

3. Composites - metal matrix composites (MMCs) Fibers: Cont s - C, SiC, B, Al 2 O 3 Discont s - C, Al 2 O 3, SiC whiskers Fibers: Cont s - C, SiC, B, Al 2 O 3 Discont s - C, Al 2 O 3, SiC whiskers May get rxn betwn phases at hi T Matrix mat'ls

4. Composites - ceramic matrix composites (CMCs) Particulates, fibers: SiC, B, Al 2 O 3, C, SiC & Si 3 N 4 whiskers Particulates, fibers: SiC, B, Al 2 O 3, C, SiC & Si 3 N 4 whiskers Improve fracture toughness: slow crack growth deflect crack tips redistribute stresses around crack tips bridge crack tips slow crack growth deflect crack tips redistribute stresses around crack tips bridge crack tips Matrix

5. Composites - polymer matrix composites (PMCs) Fibers: mainly - glass (GFRPs), carbon (CFRPs), aramid, others - B, SiC, Al 2 O 3 Fibers: mainly - glass (GFRPs), carbon (CFRPs), aramid, others - B, SiC, Al 2 O 3

6. Composites Fibers - variables amount fiber length distribution orientation Fibers - variables amount fiber length distribution orientation Fiber orientation can be random aligned intermediate Fiber orientation can be random aligned intermediate

7. Crystal whiskers - SiC

8. Composites - polymer matrix composites (PMCs) Fibers: mainly - glass (GFRPs), carbon (CFRPs), aramid, others - B, SiC, Al 2 O 3 Fibers: mainly - glass (GFRPs), carbon (CFRPs), aramid, others - B, SiC, Al 2 O 3

9. Composites - polymer matrix composites (PMCs) Fibers: mainly - glass (GFRPs), carbon (CFRPs), aramid, others - B, SiC, Al 2 O 3 Fibers: mainly - glass (GFRPs), carbon (CFRPs), aramid, others - B, SiC, Al 2 O 3

10. Composites - polymer matrix composites (PMCs) Fibers: mainly - glass (GFRPs), carbon (CFRPs), aramid, others - B, SiC, Al 2 O 3 Fibers: mainly - glass (GFRPs), carbon (CFRPs), aramid, others - B, SiC, Al 2 O 3

11. Composites - polymer matrix composites (PMCs) Fibers: mainly - glass (GFRPs), carbon (CFRPs), aramid, others - B, SiC, Al 2 O 3 Fibers: mainly - glass (GFRPs), carbon (CFRPs), aramid, others - B, SiC, Al 2 O 3

12. Composites - polymer matrix composites (PMCs) Fibers: mainly - glass (GFRPs), carbon (CFRPs), aramid, others - B, SiC, Al 2 O 3 Fibers: mainly - glass (GFRPs), carbon (CFRPs), aramid, others - B, SiC, Al 2 O 3

13. Composites - polymer matrix composites (PMCs) Carbon fibers frequently used as woven fabrics impregnated with an epoxy

14. Composites - polymer matrix composites (PMCs)

15. Woven carbon fiber fabrics in auto industry - 2006 BMW M6 - roof (unpainted) 'vette Z06 - front fenders, wheel wells, floor Porsche Carrera GT ($440,000) - frame Scion accessories - gear shift knob ($49), fuel-filler door ($39), roof pillar appliqués ($75-189), etc.

16. Composites - polymer matrix composites (PMCs) Matrix

17. Composites - polymer matrix composites (PMCs) Very common - polyesters, vinyl esters

18. Composites Role of matrix in FR composites: a. transfer stresses betwn fibers b. provide barrier to environment c. protect fibers Role of matrix in FR composites: a. transfer stresses betwn fibers b. provide barrier to environment c. protect fibers Matrix/fiber bond: matrix must wet fiber physical & chemical bond desirable mechanical interlocking Matrix/fiber bond: matrix must wet fiber physical & chemical bond desirable mechanical interlocking Fibers frequently coated w/ coupling agent

19. non-coupled Composites coupled

20. Composites Fibers - variables amount fiber length distribution orientation Fibers - variables amount fiber length distribution orientation

21. Composites Fibers - variables amount fiber length distribution orientation Fibers - variables amount fiber length distribution orientation Fiber orientation can be random aligned intermediate Fiber orientation can be random aligned intermediate

22. Composites