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Composite Materials:trends and challenges

Ignaas VerpoestComposite Materials Group,

Department Metallurgy and Materials Engineering, K.U.Leuvenand

Sirris-Leuven Composites Application Lab

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Composites: what?

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Composites: why?

• Ashby’s diagrams:

0.01 0.1 1 10Density, ρ (Mg/m3)

1000

100

10

1

10-1

10-2

10-3

10-4

Youn

g’s

mod

ulus

E (G

Pa)

Modulus - Density

foams

Polymers

Elastomers

Naturalmaterials

Composites

Metals

Ceramics

Plate bending

Tension

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Composites: why?

Conclusion: High specific strength and stiffnesslighter structuresLess energy consumption during manufacturing ànd use

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Composites: how important?

• Annual production of fibres for composites (estimations):– Glass fibres: 250.000 ton– Carbon fibres: 30.000 ton– Natural fibres: 40.000 ton– …compared to

• Steel: 800.000.000 ton• Polymers: 120.000.000 ton

• Annual growth rates of (some) composite applications– thermoplastic matrix composites : 8 % (now 37% market share)– closed moulding (RTM, RTM-light, infusion): 13 % yearly (now 10 % market

share in EU)– Aerospace structures: +11% p.a.– Wind energy composites: +16 % p.a.

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Composites: how important?

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Trends and challenges

TRENDS1. Proliferation of carbon fibres

2. Intelligent fibre architectures

3. Sustainable composites

4. Automated manufacturing

5. Recycling

6. …and nano?

CHALLENGES

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Trend 1: the proliferation of carbon fibres

• Carbon fibres:– started in aerospace in ’80s– Developed into sports and industrial applications in ’90’s– Are now penetrating into ‘high volume applications’ because of

• Long term perspective for stable costs (possibly decreasing)• Strong emphasis on sustainable, hence low energy consumption

products

• Example: BMW decided – Their “city car” (electrical or

hybrid) will be a carbon fibre composite car

– They will build their own carbon fibre manufacturing plant (together with SGL)

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Trend 2: intelligent fibre architectures

• From individual textile layers… to structurally stitched components!

2D Weaves

3D Weaves Knitted fabrics

Braids

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Trend 3: Sustainable composites

• Natural fibres: strong increase in

• Developments for composites

• Industrial interest

• Biopolymers– Preferred route should

• No compete with food

• Add little ‘chemistry’

Gluten

ResinBio-based

Polymer or CompositeMaterial

Controlled-releaseNitrogenFertilizer

Wheat

agriculture

Starch

industrialprocessing

recycling

chemical or(bio)catalyticmodification

polymerprocessing

Compost

composting

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Trend 4: automated manufacturing

• Driven by trend to ‘high volume applications’– Already happening in

• Sports equipment• Aerospace:

– at hundreds of composite aeroplanes/year– Thousands for similar components have to be produced– Hence automation is needed!

– Soon expected in automotive!

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Trend 5: recycling

• Necessity for ‘high volume applications’ • Two developments:

– Glass fibre composites:• Trend towards thermoplastic composites• Potential for alternative fibres which improve recyclability:

– Basalt fibres– Natural fibres– Steel fibres

– Carbon fibre composites:• Processes for recovery of carbon fibres are ready to operate!

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Trend 6: and nano?

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Meso

Micro

Nano

Fabric architecture

Fibers inside yarns

Structure of matrix

Multiphase epoxy Carbon nanotubes

Cracks in transverse ply Debonding at matrix/fiber interface

stiffness

failure resistance

Trend 6: … and nano?

4

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Trends and challenges

TRENDS1. Proliferation of carbon fibres

2. Intelligent fibre architectures

3. Sustainable composites

4. Automated manufacturing

5. Recycling

6. …and nano?

CHALLENGES