1. ME 201: Engineering Materials
Course Objective...
Introduce fundamental concepts in Materials
Science
You will learn about:
• material types & structure
• how structure dictates properties
• how processing can change structure
This course will help you to:
• choose the right material for a particular application
• realize new design opportunities

2. LECTURES Instructor: Dr. Mehr Nigar Grading Policy:
• Quizzes & Assignments* %
• Mid-Term Exam* %
• End-Semester Exam %
*No Make-ups under any circumstances.
*Discuss potential conflicts beforehand.

3. COURSE MATERIALS Required text:
• Materials Science and Engineering: An Introduction
W.D. Callister, Jr., 7th edition, John Wiley and Sons, Inc. (2007). ( or latest edition)

4. COURSE WEBSITES Text Website: http://www.wiley.com/college/callister
Additional Chapters (Chapters 19-23)
Complete solutions to selected problems
Links to other web resources
Extended learning objectives
Self-assessment exercises

5. CHAPTER 1

7. Chapter 1 - Introduction
What is materials science?
Why should we know about it?
Materials drive our society
Stone Age (~ 2.5 million BC)
Bronze Age (~ 3500 BC)
Iron Age (~ 1000 BC)
Now?
Silicon Age?
Polymer Age?
The approximate dates for the beginnings of Stone, Bronze, and Iron Ages were 2.5 million
BC, 3500 BC and 1000 BC, respectively.
“materials science” involves investigating the relationships that exist between the structures and properties of materials. In contrast, “materials engineering” is, on the basis of these structure–property correlations, designing or engineering the structure of a material to produce a predetermined set of properties

8. The approximate dates for the beginnings of Stone, Bronze, and Iron Ages were 2.5 million
BC, 3500 BC and 1000 BC, respectively.

9. The Iron Pillar from Delhi (built in the late 4th or early 5th century; some historians have dated it to as early as 912 B.C!) 7.3 m tall, with one meter below the ground; the diameter is 48 centimeters at the foot, tapering to 29 cm at the top, just below the base of the wonderfully crafted capital; it weighs approximately 6.5 tones, and was manufactured by forged welding

10. Example – Hip Implant
Adapted from Fig , Callister 7e.

11. Types of Materials
Metals: Metallic bonding  free electrons not attracted to any one particular nucleus
Strong, ductile
high thermal & electrical conductivity
opaque, reflective.
Polymers/plastics: Covalent bonding  sharing of e’s
Soft, ductile, low strength, low density
thermal & electrical insulators
Optically translucent or transparent.
Ceramics: ionic bonding (refractory) – compounds of metallic & non-metallic elements (oxides, carbides, nitrides, sulfides)
Brittle, glassy, capable of elastic deformation only
non-conducting (insulators)
Metals have high thermal & electrical conductivity because valence electrons are free to roam

12. Types of Materials
Materials recommended for cutting with zirconia scissors: Biological material (cartilage), Kevlar*, PTFE, magnetic tape, cable wrap materials, some electrical wire, certain film materials and fabric. Do Not use ceramic scissors for glass, fiberglass, thick cardboard, thick cloth, metal and alumina composites. Price ~ $55 cf $5 for regular good quality metal scissors

13. Densities of Various Materials

14. Structure, Processing, & Properties
• Properties depend on structure
ex: hardness vs structure of steel
(d)
30 mm 6 00 5 00
(c)
4 mm
Data obtained from Figs (a)
and with 4 wt% C composition,
and from Fig and associated
discussion, Callister 7e.
Micrographs adapted from (a) Fig.
10.19; (b) Fig. 9.30;(c) Fig ;
and (d) Fig , Callister 7e. 4 00
(b)
30 mm
(a)
30 mm
Hardness (BHN) 3 00 2 00
100
0.01
0.1 1 10
100
1000
Cooling Rate (ºC/s)
• Processing can change structure
ex: structure vs cooling rate of steel

15. ELECTRICAL • Electrical Resistivity of Copper: Resistivity, r T (°C)
-200
-100
Cu at%Ni
Cu at%Ni
deformed Cu at%Ni 1 2 3 4 5 6
Resistivity, r
(10-8 Ohm-m)
Cu at%Ni
“Pure” Cu
Adapted from Fig. 18.8, Callister 7e.
(Fig adapted from: J.O. Linde,
Ann Physik 5, 219 (1932); and
C.A. Wert and R.M. Thomson,
Physics of Solids, 2nd edition,
McGraw-Hill Company, New York,
1970.)
• Adding “impurity” atoms to Cu increases resistivity.
• Deforming Cu increases resistivity.

16. OPTICAL • Transmittance:
--Aluminum oxide may be transparent, translucent, or
opaque depending on the material structure.
polycrystal:
low porosity
polycrystal:
high porosity
single crystal
Adapted from Fig. 1.2,
Callister 7e.
(Specimen preparation,
P.A. Lessing; photo by S. Tanner.)

17. DETERIORATIVE • Stress & Saltwater... • Heat treatment: slows
--causes cracks!
• Heat treatment: slows
crack speed in salt water!
“held at
160ºC for 1 hr
before testing”
increasing load
crack speed (m/s)
“as-is” 10
-10 -8
Alloy 7178 tested in
saturated aqueous NaCl
solution at 23ºC
Adapted from Fig (b), R.W. Hertzberg, "Deformation and Fracture Mechanics of Engineering Materials" (4th ed.), p. 505, John Wiley and Sons, (Original source: Markus O. Speidel, Brown Boveri Co.)
Adapted from chapter-opening photograph, Chapter 17, Callister 7e.
(from Marine Corrosion, Causes, and Prevention, John Wiley and Sons, Inc., 1975.)
4 mm
--material:
7150-T651 Al "alloy"
(Zn,Cu,Mg,Zr)
Adapted from Fig ,
Callister 7e. (Fig provided courtesy of G.H.
Narayanan and A.G. Miller, Boeing Commercial
Airplane Company.)

18. The Materials Selection Process1.
Pick Application
Determine required Properties
Properties: mechanical, electrical, thermal,
magnetic, optical, deteriorative. 2.
Properties
Identify candidate Material(s)
Material: structure, composition. 3.
Material
Identify required Processing
Processing: changes structure and overall shape
ex: casting, sintering, vapor deposition, doping
forming, joining, annealing.

19. Selection Criteria for Beverage Container
provide a barrier to the passage of carbon dioxide, which is under pressure in the container;
be nontoxic, unreactive with the beverage, and, preferably be recyclable;
be relatively strong, and capable of surviving a drop from a height of several feet when containing the beverage;
be inexpensive and the cost to fabricate the final shape should be relatively low;
if optically transparent, retain its optical clarity;
capable of being produced having different colors and/or able to be adorned with decorative labels.

20. Aluminum alloy is relatively strong (but easily
dented), is a very good barrier to the diffusion of carbon dioxide, is easily recycled, beverages are cooled rapidly, and labels may be painted onto its surface, however they are opaque and expensive
to produce.
Glass is impervious to the passage of carbon dioxide, is a relatively inexpensive material, may be recycled,
but it cracks and fractures easily, and glass bottles are relatively heavy
Plastic is relatively strong, may be made optically transparent ,is inexpensive and lightweight, and is recyclable, it is not as impervious to the passage of carbon dioxide as aluminum and glass

21. SUMMARY Course Goals: • Use the right material for the job.
• Understand the relation between properties,
structure, and processing.
• Recognize new design opportunities offered
by materials selection.