1. 材料科学与工程专业英语 Special English for Materials Science and Engineering
Unit16 Introduction to Composites
Unit 17 Properties of composite mateirals

2. Composites
A composite materials is commonly defined as a combination of two or more distinct materials that cannot be achieved by any of the components acting alone.
Combine materials with the objective of
getting a more desirable combination of
properties

3. Applications:
Aerospace industry
Sporting Goods Industry
Automotive Industry
Home Appliance Industry

4. Reinforced concrete:钢筋混凝土 Fiberglass:纤维玻璃 Resin：树脂
Words
Reinforced concrete:钢筋混凝土
Fiberglass:纤维玻璃
Resin：树脂
Questions
What is the composite? Can you give some examples?
Which two phases do the composite materials have?

5. Kevlar：凯夫拉尔，纤维B（一种质地牢固重量轻的合成纤维）；杜邦公司使用在芳族聚酰胺纤维商品上的注册商标
Words
Graphite：石墨
Kevlar：凯夫拉尔，纤维B（一种质地牢固重量轻的合成纤维）；杜邦公司使用在芳族聚酰胺纤维商品上的注册商标
Epoxy resin：环氧树脂

6. Terminology/Classification
• Composites:
-- Multiphase material with significant
proportions of each phase.
woven
fibers
cross
section
view
0.5 mm
• Matrix:
-- The continuous phase
-- Purpose is to:
- transfer stress to other phases
- protect phases from environment
-- Classification: MMC, CMC, PMC
metal
ceramic
polymer
• Dispersed phase:
-- Purpose: enhance matrix properties.
MMC: increase sy, TS, creep resist.
CMC: increase Kc
PMC: increase E, sy, TS, creep resist.
-- Classification: Particle, fiber, structural
Reprinted with permission from
D. Hull and T.W. Clyne, An Introduction to Composite Materials, 2nd ed., Cambridge University Press, New York, 1996, Fig. 3.6, p. 47. 6

7. Composite Survey: Fiber
Particle-reinforced
Fiber-reinforced
Structural
Fibers themselves are very strong
Provide significant strength improvement to material
Ex: fiber-glass
Continuous glass filaments in a polymer matrix
Strength due to fibers
Polymer simply holds them in place and environmentally protects them 7

8. Composite Survey: Fiber
Particle-reinforced
Fiber-reinforced
Structural
Fiber Materials
Whiskers - Thin single crystals - large length to diameter ratio
graphite, SiN, SiC
high crystal perfection – extremely strong, strongest known
very expensive
Fibers
polycrystalline or amorphous
generally polymers or ceramics
Ex: Al2O3 , Aramid, E-glass, Boron, UHMWPE
Wires
Metal – steel, Mo, W 8

9. Fiber Alignment aligned continuous aligned random discontinuous
Adapted from Fig. 16.8, Callister 7e.
aligned
continuous
aligned random
discontinuous 9

10. Properties of composite materials
Unit 17
Properties of composite materials

11. Words Question Isotropic:各向同性的 Orthotropic：正交各向异性的 Moment：力矩
Mechanics of composite materials
Words
Isotropic:各向同性的
Orthotropic：正交各向异性的
Moment：力矩
Thermoset：热固体
Thermoplastic：热塑体
Orientation：取向
Poisson’s ratio：泊松比
Question
What is the difference between isotropic materials and orthotropic materials

12. Words Question Delamination: 脱层 buckling 压曲；压弯 Net section:净截面
Failure of composites
Words
Delamination: 脱层
buckling 压曲；压弯
Net section:净截面
Question
What is the difference between isotropic materials and orthotropic materials

13. Advanced Aerospace Application:
Advantage of composite materials
Why use composites?
Strength, stiffness and lightness
Boeing 767 (and in 777, 787 airplanes w/ the latest, full wing box is composite):
Advanced Aerospace Application: