Composites overview Artificial combination of matrix phase dispersed

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

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

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

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

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

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

Crystal whiskers - Si. C

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

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

Composites - polymer matrix composites (PMCs)

Composites - polymer matrix composites (PMCs) Woven carbon fiber fabrics in auto industry - 2006 BMW M 6 - roof (unpainted) 'vette Z 06 - 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.

Composites - polymer matrix composites (PMCs) Matrix

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

Composites 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 Fibers frequently coated w/ coupling agent

Composites non-coupled

Composites Fibers - variables amount fiber length distribution orientation

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

Composites