Fundamentals of Materials

Science (MNF 212)

Dr. Gamal AbdouDepartment of Manufacturing Engineering and Production

1

Fundamentals of Material Science Dr. Gamal Abdou

Course Outline

Lecturer: Dr. Gamal Abdou

Course Outline:1. Introduction to Engineering Materials

2. Atomic Structure and Interatomic Bonding

3. Structure of Crystalline Materials

4. Imperfections in Solid

5. Diffusion

6. Strengthening Mechanisms

7. Mechanical Properties

8. Electrical, Thermal, Optical, and Magnetic Properties

9. Fracture, Fatigue, and creep

Exams, Projects, Practices:• Workshop and/or classroom practices (10%)

• Midterm Exam (10%)

• Practical Exam (20)

• Term Exam (60%)

Fundamentals of Materials Science

Course Resources

• Lectures Notes Dr. Gamal Abdou

• Labs experiments

• Tutorials exercises

• Text Book References

• W.D. Callister “Fundamentals of Materials Science and Engineering”

” , 5th edition, Wiley

.

Fundamentals of Materials Science

Fundamentals of Material Science

CHAPTER 1

Introduction to Engineering Materials

Fundamentals of Material Science Dr. Gamal Abdou

Why Materials ???

Introduction to Engineering Materials

Properties of materials

Mechanical properties of materialsStrength, Toughness, Hardness, Ductility,

Elasticity, Fatigue and Creep

Chemical propertiesOxidation, Corrosion, Flammability, Toxicity, …

Physical propertiesDensity, Specific heat, Melting and boiling point,

Thermal expansion and conductivity,

Electrical and magnetic properties

General properties of Ceramics:

1. High melting points and high chemical stabilities.

2. High hardness and high temperature strength.

3. Very brittle.

4. Poor electrical conductors.

5. High strength on compression.

6. They can be crystalline (ceramics), non-crystalline

(glass) or mixture of both glass- ceramics).

7. Ceramics specific gravity(density) = 2.5 gm/mm2

General properties of Polymers:

1. Non-crystalline, but some consist of mixtures of both

crystalline and non-crystalline regions.

2. Low densities and low rigidity.

3. Poor electrical conductors due to the nature of the

atomic bonding.

4. High corrosion resistant but not used at high

temperatures.

5. Good strength to weight ratio.

6. Polymer specific gravity(density) ≈ 1.2 gm/mm2

Composites

A number of composite materials have been engineered that

consist of more than one material type. Usually they consist of:

a) Reinforcement phase(e. g. fiber)

b) Binder phase (e.g. compliant matrix)

Advantage of composite:

1. High strength and stiffness.

2. High corrosion resistance.

3. High wear resistance.

4. High thermal insulation.

5. Low weight ratio.

General Properties and Applications of

Ferrous Alloys

• Ferrous alloys are useful metals in terms of

mechanical, physical and chemical

properties.

• Alloys contain iron as their base metal.

• Carbon steels are least expensive of all

metals while stainless steels is costly.

Carbon and alloy steels

Carbon steels

• Classified as low, medium and high:

1. Low-carbon steel or mild steel, < 0.3%C,

bolts, nuts and sheet plates.

2. Medium-carbon steel, 0.3% ~ 0.6%C,

machinery, automotive and agricultural

equipment.

3. High-carbon steel, > 0.60% C, springs,

cutlery, cable.

Carbon and alloy steels

Alloy steels

• Steels containing significant amounts of

alloying elements.

• Structural-grade alloy steels used for

construction industries due to high strength.

• Other alloy steels are used for its strength,

hardness, resistance to creep and fatigue,

and toughness.

• It may heat treated to obtain the desired

properties.

Carbon and alloy steels

High-strength low-alloy steels

• Improved strength-to-weight ratio.

• Used in automobile bodies to reduce weight

and in agricultural equipment.

• Some examples are:

1. Dual-phase steels

2. Micro alloyed steels

3. Nano-alloyed steels

Stainless steels

• Characterized by their corrosion resistance,

high strength and ductility, and high

chromium content.

• Stainless as a film of chromium oxide protects

the metal from corrosion.

Stainless steels

• Five types of stainless steels:

1. Austenitic steels

2. Ferritic steels

3. Martensitic steels

4. Precipitation-hardening (PH) steels

5. Duplex-structure steels

Typical Selection of Carbon and Alloy Steels

for Various Applications

TABLE 5.1

Product Steel Product Steel

Aircraft forgings,

tubing, fittings

Automobile bodies

Axles

Ball bearings and races

Bolts

Camshafts

Chains (transmission)

Coil springs

Connecting rods

Crankshafts (forged)

4140, 8740

1010

1040, 4140

52100

1035, 4042, 4815

1020, 1040

3135, 3140

4063

1040, 3141, 4340

1045, 1145, 3135, 3140

Differential gears

Gears (car and truck)

Landing gear

Lock washers

Nuts

Railroad rails and wheels

Springs (coil)

Springs (leaf)

Tubing

Wire

Wire (music)

4023

4027, 4032

4140, 4340, 8740

1060

3130

1080

1095, 4063, 6150

1085, 4063, 9260, 6150

1040

1045, 1055

1085

Mechanical Properties of Selected Carbon

and Alloy Steels in Various Conditions

TABLE 5.2 Typical Mechanical Properties of Selected Carbon and Alloy Steels in the Hot-Rolled,

Normalized, and Annealed Condition

AISI Condition Ultimate

tensile

strength

(MPa)

Yield

Strength

(MPa)

Elongation in

50 mm (%)

Reduction of

area (%)

Hardness

(HB)

1020

1080

3140

4340

8620

As-rolled

Normalized

Annealed

As-rolled

Normalized

Annealed

Normalized

Annealed

Normalized

Annealed

Normalized

Annealed

448

441

393

1010

965

615

891

689

1279

744

632

536

346

330

294

586

524

375

599

422

861

472

385

357

36

35

36

12

11

24

19

24

12

22

26

31

59

67

66

17

20

45

57

50

36

49

59

62

143

131

111

293

293

174

262

197

363

217

183

149

AISI Designation for High-Strength Sheet Steel

TABLE 5.3

Yield Strength Chemical

Composition

Deoxidation

Practice

psi x 103

MPa

35

40

45

50

60

70

80

100

120

140

240

275

310

350

415

485

550

690

830

970

S = structural alloy

X = low alloy

W = weathering

D = dual phase

F = killed plus sulfide inclusion control

K = killed

O = nonkilled

Room-Temperature Mechanical Properties and

Applications of Annealed Stainless Steels

TABLE 5.4 Room-Temperature Mechanical Properties and Typical Applications of Selected Annealed

Stainless Steels

AISI

(UNS)

Ultimate

tensile

strength

(MPa)

Yield

strength

(MPa)

Elongation

in 50 mm

(%) Characteristics and typical applications

303

(S30300)

550–620 240–260 53–50 Screw machine products, shafts, valves, bolts,

bushings, and nuts; aircraft fittings; bolts; nuts;

rivets; screws; studs.

304

(S30400)

565–620 240–290 60–55 Chemical and food processing equipment,

brewing equipment, cryogenic vessels, gutters,

downspouts, and flashings.

316

(S31600)

550–590 210–290 60–55 High corrosion resistance and high creep strength.

Chemical and pulp handling equipment,

photographic equipment, brandy vats, fertilizer

parts, ketchup cooking kettles, and yeast tubs.

410

(S41000)

480–520 240–310 35–25 Machine parts, pump shafts, bolts, bushings, coal

chutes, cutlery, tackle, hardware, jet engine parts,

mining machinery, rifle barrels, screws, and

valves.

416

(S41600)

480–520 275 30–20 Aircraft fittings, bolts, nuts, fire extinguisher

inserts, rivets, and screws.

Tool and die steels

• Designed for high strength, impact

toughness, and wear resistance at a range of

temperatures.

Aluminium and aluminium alloys

• Factors for selecting are:

1. High strength to weight ratio

2. Resistance to corrosion

3. High thermal and electrical conductivity

4. Ease of machinability

5. Non-magnetic

Magnesium and magnesium alloys

• Magnesium (Mg) is the lightest metal.

• Alloys are used in structural and non-

structural applications.

• Typical uses of magnesium alloys are aircraft

and missile components.

• Also has good vibration-damping

characteristics.

Copper and copper alloys

• Copper alloys have electrical and mechanical

properties, corrosion resistance, thermal

conductivity and wear resistance.

• Applications are electronic components,

springs and heat exchangers.

• Brass is an alloy of copper and zinc.

• Bronze is an alloy of copper and tin.

Nickel and nickel alloys

• Nickel (Ni) has strength, toughness, and

corrosion resistance to metals.

• Used in stainless steels and nickel-base

alloys.

• Alloys are used for high temperature

applications, such as jet-engine components

and rockets.

Superalloys

• Superalloys are high-temperature alloys use

in jet engines, gas turbines and reciprocating

engines.

Titanium and titanium alloys

• Titanium (Ti) is expensive, has high strength-

to-weight ratio and corrosion resistance.

• Used as components for aircrafts, jet-

engines, racing-cars and marine crafts.

Refractory metals

• Refractory metals have a high melting point

and retain their strength at elevated

temperatures.

• Applications are electronics, nuclear power

and chemical industries.

• Molybdenum, columbium, tungsten, and

tantalum are referred to as refractory metal.

Other nonferrous metals

1. Beryllium

2. Zirconium

3. Low-melting-point metals:

- Lead

- Zinc

- Tin

4. Precious metals:

- Gold

- Silver

- Platinum

Special metals and alloys

1. Shape-memory alloys (i.e. eyeglass frame, helical

spring)

2. Amorphous alloys (Metallic Glass)

3. Nanomaterials

4. Metal foams

Ceramics

•Traditional ceramics

• clays: kaolinite

• silica: quartz, sandstone

• alumina

• silicon carbide

•New ceramics

• oxide ceramics : alumina

• carbides : silicon carbide, titanium carbide, etc.

• nitrides : silicon nitride, boron nitiride, etc.

Polymers

• Thermoplastics - reversible in phase by heating and cooling. Solid phase at room temperature and liquid phase at elevated temperature.

• Thermosets - irreversible in phase by heating and cooling. Change to liquid phase when heated, then follow with an irreversible exothermic chemical reaction. Remain in solid phase subsequently.

• Elastomers - Rubbers

• Metal Matrix Composites (MMC)

Mixture of ceramics and metals reinforced by strong, high-stiffness fibers

• Ceramic Matrix Composites (CMC)

Ceramics such as aluminum oxide and silicon carbide embedded with fibers for improved properties, especially high temperature applications.

• Polymer Matrix Composites (PMC)

Thermosets or thermoplastics mixed with fiber reinforcement or powder.

Composite

Fig. 1 The role of Materials Science and Materials

Engineering

Materials Science and Materials Engineering