1. Fundamentals of materials science and engineering

2. Introduction to Materials Science and Engineering
Chapter 1
Introduction to Materials Science
and Engineering

3. Have You Ever Wondered?
What do materials scientists and engineers study?
How sheet steel can be processed to produce a high-strength，
lightweight，energy absorbing，malleable（可塑的，可锻的）
material used in the manufacture of car chassis（底盘）?
Can we make flexible and lightweight electronic circuits
using plastics?
What is a “smart material”?

4. outline What is Materials Science and Engineering?
Classification of Materials
Environmental and Other Effects
Materials Design and Selection

5. 1-1 What is Materials Science and Engineering?
1. Definition
Materials Science and Engineering (MSE) is an interdisciplinary field concerned with inventing new materials and improving previously known materials by developing a deeper understanding of the microstructure-composition-synthesis-processing relationship.

6. Means the chemical make-up of a material
▲The term Composition
Means the chemical make-up of a material
▲Structure
A description of the arrangement of atoms ,
as seen at different levels of detail.
▲Synthesis
Refers to how materials are made from naturally
occuring or man-made chemicals.
▲Processing
Means how materials are shaped into useful components
to cause changes in the properties of different materials.

7. Composition;
Strength;
Weight;
Energy absorption properties;
Malleability (formability)
Strength-to-weight ratio is the strength of a material divided by its density; materials with a high strength-to-weight ratio are strong but lightweight.
Figure Application of the tetrahedron of materials science and engineering to sheet steels for automotive chassis. Note that the microstructure-synthesis and processing-composition are all interconnected and affect the performance-to-cost ratio

8. 结实的；耐用的；坚固的
[rəu′bʌst]
Figure Application of the tetrahedron of materials science and engineering to semiconducting polymers for microelectronics.

9. Tetrahedron of MSE
Performance
Cast
What is the current carrying capacity?
What is the cast of cooling and fabrication?
Composition
YBa2Cu3O7-x
YBa2Ca3Cu4O11
YSr2Ca2Cu3O10
Synthesis and processing
How can pure, homogeneous, and fine powders of well-defined stoichiometry be made?
How do we make long lengths of wires?
Microstructure
What features of the structure limit the current carrying capacity?
What is the texture of the material?
Figure Application of the tetrahedron of materials science and engineering to ceramic superconductors. Note that the microstructure-synthesis and processing-composition are all interconnected and affect the performance-to-cost ratio

10. 3. Materials Engineering
2. Materials Science
The emphasis is on the underlying relationships between the synthesis and processing, structure, and properties of materials.
3. Materials Engineering
The focus is on how to translate or transform
materials into a useful device or structure.

11. Application OF Tetrahedron :
a sample product –ceramic superconductors invented in 1986
(1)DISCOVERY
(2)LIMITATION
(3)IMPROVEMENT
(4)SOLUTION
(5)BRITTLE
(6)SOLUTION

12. 1-2 Classification Of Materials
According to different properties
Functional Classification of Materials
Classification of Materials Based on Structure (microstructure)

13. 1.According to different properties
Classification Properties Application
Metals good electrical and thermal conductivity automobile engine
(steels, aluminum, relatively high strength, stiffness, aircraft, electrical
magnesium) ductivity, formability conductor wire
Ceramics high melting point, strength, hardness house computer chip
(Si , SiO2 ,Al2O3 , capacitors, electrical insulation
,MgO ,SiC ,Si3N4 ) sanitaryware, abrasive
Polymers
electrical resistivity, thermal insulation, food packaging
low strength liquid crystal displays
(LCD)
Semiconductor
(Silicon, GaAs ) convert electrical signals to light transistors, diodes
lasers, etc integrated circuits
Composites
high hardness, good shock resistance, sports equipment, fiberglass
high strength-to-weight ratio aircraft ,matrix
Biomaterials
finger joint teeth 手指关节
生物功能性(biofunctionability )
和生物相容性(biocompatibility )
metallic,ceramic,
polymer materials

14. Representative strengths of various categories of materials
环氧树脂
芳纶纤维
聚酰亚胺
聚醚酮树脂
聚酯纤维 ，涤纶
聚乙烯
Figure
Representative strengths of various categories of materials

15. 2.Functional Classification of Materials
Aerospace（航空航天） –light materials
Biomedical Materials
Electronic Materials
Energy Technology and Environmental Technology
Magnetic Materials
Photonic or Optical Materials(光学材料）
Smart Materials
Structural Materials

16. 压电陶瓷(锆钛酸铅) (Y3Al5O12) (Y3Al5O12)
YAG: yttrium aluminum garnet
(Y3Al5O12)
Aerospace
C-C composites,
ITO: In2O3-SnO2
铟-锡
SiO2, Amorphous
silicon, Ai-alloys
Biomedical
Structural
Hydroxyapatite羟磷灰石
MR: magnetorheology
Superalloys
磁流体
Steel
Titanium alloys,
Aluminum alloys
Stainless steels
PZT: lead zicornium titanate
Concrete
Shape-memory
alloys
Fiberglass
Plastic, Wood
Plastics, PZT
压电陶瓷(锆钛酸铅)
Classification of
Functional
Materials
Electronic
Materials
Smart materials
Si, GaAs, Ge,
BaTiO3, PZT,
YBa2Cu3O7, Al,
Cu, W, Conducting
polymer
PZT
Shape-memory
alloys
(Y3Al5O12)
(Y3Al5O12)
MR fluid
Polymer gels
Optical
Materials
Energy
Technology &
Environmental
SiO2, GaAs
Figure Functional classification of materials. Notice that metals, plastics, and ceramics occur in different categories. A limited number of examples in each category is provided
UO2, Ni-Cd, ZrO2,
Glasses, Al2O3
Magnetic
Materials
LiCoC2, Amorphous
Si:H
YAG, ITO
Fe, Fe-Si, NiZn
And MnZn ferrites;
Co-Pt-Ta-Cr
g-Fe2O3

17. 3.Classification of Materials Based on Structure (microstructure)
Crystal （晶体） the material’s atoms are arranged in a periodic fashion.
Amorphous（非晶体）----- the material’s atoms do not have a long-range order.
Single crystals（单晶） some crystalline materials may be in the form of one crystal.
Polycrystals（多晶）--- some crystalline materials consist of many crystals or grains.

18. MSE
5 nm
Optical
SEM
XRD, TEM

19. （translucent; semitransparent）
• transparency 透明度:
--氧化铝因其结构不同而透明、半透明、不透明 单晶
(transparent)
多晶：低孔隙度
（translucent; semitransparent）
多晶：高孔隙度
（opaque ）
Adapted from Fig. 1.2,
Callister 7e.
(Specimen preparation,
P.A. Lessing; photo by S. Tanner.) 19 19

20. 1-3 Environmental and Other Effects
Temperature
Corrosion
Fatigue
Strain Rate

21. 1.Temperature High temperature -----change the structure of
ceramics and cause polymers to melt or char
Low temperature ----cause a metal or polymers to fail in a brittle manner, even though the applied loads are low.

22. TEMPERATURE
Figure Increasing temperature normally reduces the strength of a material. Polymers are suitable only at low temperatures. Some composites, special alloys, and ceramics, have excellent properties at high temperatures

23. Figure A section through a jet engine
Figure A section through a jet engine. The forward compression section operates at low to medium temperatures, and titanium parts are often used. The rear combustion（尾部燃烧） section operates at high temperatures and nickel-based superalloys are required. The outside shell experiences low temperatures, and aluminum and composites are satisfactory. (Courtesy of GE Aircraft Engines.)
Figure A variety of complex ceramic components, including impellers（叶轮） and blades, which allow turbine engines to operate more efficiently at higher temperatures. (Courtesy of Certech, Inc.)

24. Figure Integrated circuits for computers and other electronic devices rely on the unique electrical behavior of semiconducting materials. (Courtesy of Rogers Corporation.)
Figure Polymers are used in a variety of electronic devices, including these computer dip
switches, where moisture resistance and low conductivity are required. (Courtesy of CTS Corporation.)

25. Figure The X-wing for advanced helicopters relies on a material composed of a carbon-fiber-reinforced polymer. (Courtesy of Sikorsky Aircraft Division—United Technologies Corporation.)

26. 2.Corrosion oxygen or other gases Liquid
Radiation（辐射）, atomic oxygen, debris （碎石，废石）

27. 2.Corrosion oxygen or other gases
(1)Most metals and polymers react with oxygen or other gases, particularly at elevated temperatures.
(2) Metals and ceramics may disintegrate .
(3) Nonoxide ceramics and polymers may oxidize.

28. liquid acid （酸） alkali （碱） salt（盐）---leading to premature failure
Radiation（辐射）, atomic oxygen, debris （碎石，废石）
In space applications, we may have to consider the effects
of the presence of radiation, the presence of atomic oxygen,
and the impact from debris .

29. 3.Fatigue
load and unload the material thousands of times small cracks cracks grow materials fail

30. 4.Strain Rate
If we pull it slowly, the material can be stretched significantly.
If we pull it fast, the material snaps.

31. 1-4 Materials Design and Selection
Physical and mechanical properties
Design for a given application a number of factors economical solution
Protect environment
Recycling of the materials
composition
synthesis and processing
internal structure

32. A good engineer will consider:
the effect of how the material is made;
what exactly is the composition of the candidate material for the application being considered;
processing have to be done for shaping the material or fabricating a component;
the structure of the material after processing into a component or device ;
the environment in which the material will be used;
cost -to-performance ratio.

33. The knowledge of principles of materials science and engineering will empower you with the fundamental concepts.
These will allow you to make technically sound decisions in designing with engineered materials.