現在CFRP比較成熟了；很多戰鬥機上用

CFRP (Carbon Fiber Reinforced Polymer) vs. Aluminum is a common comparison in aerospace, automotive, and other high-performance engineering applications. Here’s a detailed breakdown:

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1. Material Properties

Property	CFRP (Carbon Fiber)	Aluminum (e.g., 6061, 7075)
Density	~1.6 g/cm?	~2.7 g/cm?
Tensile Strength	~500–1500 MPa (directional)	~290–570 MPa
Stiffness (Modulus)	~70–150 GPa (anisotropic)	~69–80 GPa (isotropic)
Fatigue Resistance	Very good	Moderate
Corrosion Resistance	Excellent (non-metallic)	Good (can oxidize, but manageable)
Thermal Conductivity	Low (~5–10 W/m·K)	High (~120–220 W/m·K)
Thermal Expansion	Very low (near zero)	Relatively high (~23 ?m/m·K for 6061)

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? 2. Usage in Aerospace

Use Case	CFRP	Aluminum
Aircraft Bodies	Modern aircraft (e.g., Boeing 787, Airbus A350)	Older gen aircraft (e.g., Boeing 737, A320)
Wings/Fuselage	Superior strength-to-weight ratio	Easier to fabricate and repair
Satellites/Space	Widely used due to low weight and no corrosion	Used with surface treatments

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? 3. Manufacturing Cost

Factor	CFRP	Aluminum
Manufacturing	Complex layup, curing, autoclaves often needed	Simple casting, forging, machining
Repairability	Difficult, needs specialist tools and skills	Easy to weld, rivet, replace
Cost	Much more expensive (5–20× aluminum)	Relatively cheap and widely available

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4. Summary: When to Use What

Situation	Preferred Material
Max weight savings needed	CFRP
Simple, cost-effective solution	Aluminum
High-temperature environments	Aluminum (CFRP degrades)
Custom, performance-optimized	CFRP
Ease of fabrication/repair	Aluminum