COURSE SYLLABUS MSE 2001 Principles and Applications of Engineering Materials

Fall 2015 (August 17 - December 4)

MWF 9:05 am – 9:55 am, Boggs Building, Rm.B6

• Instructor: Prof. Wenshan Cai

• Office hours: Monday 3:00-4:00 pm. Pettit MiRC 213

• Email: wcai@gatech.edu

• Website: T-Square Site MSE-2001-O (Fall 2015). All course materials, including syllabus, lecture slides, homework assignments, and solutions, will be posted on the T-squire site.

• Teaching assistants: Kevin Chan kevinjchan@gatech.edu

Simiao Niu simiaoniu@gatech.edu

Aaron Tallman aaronetallman@gmail.com

Chia-Chi Tuan chiachituan@gatech.edu

Their office hours and location will be announced on the T-square site very soon.

• Course description:

MSE 2001 deals with the fundamentals of structure-property-processing relationships of engineering materials.

Performance

Structure

Properties

Processing

Textbook

• The lectures follow the material

presented in the textbook and

the lecture slides posted on T-

Square site.

• The course will cover Chapters

1 through 10 in the text.

• You are expected to read all

materials prior to class and

review the lecture notes on T-

square.

• Prerequisites: CHEM 1310 or

CHEM 1211K

The Science and Design of

Engineering Materials, 2nd ed.,

James P. Schaffer, Ashok Saxena,

Stephen D. Antolovich, Thomas H.

Sanders, Jr., and Steven B.

Warner, McGraw-Hill, 1999.

Homework, quizzes, exams, and grading

• Homework: Homework will be regularly assigned but not collected.

Solutions to the homework problems will be discussed in class.

Solutions to problems at the end of each chapter are available

online at https://mse2.gatech.edu/private/MSE2001/. It is the

responsibility of each student to keep up with all assignments.

• Grading: Three close book and notes, in-class exams, ten quizzes,

and a comprehensive final exam will be used to evaluate

performance with the following weights:

18% × 3 + 10% + 36% = 100%

In-class exams quizzes final exam total

• Dates for the in-class exams will be announced at least one week in

advance.

• There will be 12 unannounced quizzes. Your lowest 2 quiz scores will be

dropped. Quizzes can be given at any time during the class period. Please

make sure you have letter size papers in class.

Classroom Etiquette and Honor Code

• I expect students to behave in a manner that would be appropriate

in a college classroom. Students that exhibit disruptive behavior that

annoys others, or are counterproductive to a good learning

environment will be asked to leave and may be dropped from the

course.

• All students are expected to comply with the Georgia Tech Honor

Code. The academic Honor Code is available on the web at

http://www.honor.gatech.edu.

Topic Text materials # LecturesSyllabus & Introduction Chapter 1 2Atomic Scale Structure Chapter 2 3Crystal Structures Chapter 3 4Review for Exam 1 Chapters 1 – 3 1Exam 1 (Chapters 1 - 3) Monday, Sept.14 1Point Defects & Diffusion Chapter 4 4Crystalline Defects Chapter 5 3Noncrystalline Materials Chapter 6 3Review for Exam 2 Chapters 4 – 6 1Exam 2 (Chapters 4 - 6) Wednesday, Oct.21 1Phase Equilibria & Phase Diagrams Chapter 7 5Structural Transformations Chapter 8 4Review for Exam 3 Chapters 7 & 8 1Exam 3 (Chapters 7 - 8) Friday, Nov.13 1Mechanical Properties Chapter 9 3Electrical Properties Chapter 10 5Review for Final exam Chapters 1 – 10 2

MSE 2001 (Fall 2015) Class ScheduleNote: This is a tentative schedule and is subject to change.

Total # Lectures: 44Final exam (Chapter 1 - 10)

Lecture 1: Chapter 1(all slides are based on the presentation developed by Prof. Thomas H. Sanders, MSE)

James P. Schaffer, Ashok Saxena,

Stephen D. Antolovich, Thomas H.

Sanders, Jr. and Steven B.

Warner, The Science and Design

of Engineering Materials,

Second Edition, Irwin, Chicago,

IL, 1999.

Materials Science and

Engineering• Types of materials

• Structure-Property-Process

relationships

Major classes of materials• Metals

• Ceramics

• Polymers

• Composites

• Semiconductors

Role of Materials

• Technology determines prosperity and power

• Breakthroughs in technology are linked to the

development of new materials and processes

[examples: weapons (from swords to modern energetic materials to shock absorbing

materials), electronics (Si-based transistors in computers, phones, play stations),

aircraft and space shuttles (efficient engines, lightweight frames, temperature

insulation), telecommunications (optical fibers), solar cells, etc.]

Structure of Materials

• All matter is composed of atoms

• All atoms are composed of nucleus and electrons

• Properties of an atom are determined by: (1) number of electrons or protons in a neutral atom; (2) mass; (3) distribution of electrons in orbits; (4) energy of electrons; (5) ease of adding or removing electrons to create a charged ion

• All nucleus consist of protons and neutrons

• Properties of materials depend on what atoms they are made of and how these atoms are arranged

Structure of Materials• How atoms are held together?

• By primary (ionic, covalent, metallic) or

secondary (van der Waals) bonds

• What is the difference between primary and secondary bonds?

• Primary bonds involve either the transfer of electrons from

one atom to another or sharing electrons between atoms

• Secondary bonds occur only due to interaction between

electrical dipoles (center of positive

charge is different from the center of

negative charge; the dipole can be

either permanent, induced, or temporary)

• Primary bonds are much stronger

• Can we predict the bonding type?

• Yes, will discuss next time

• Is bonding important for understanding materials?

• Yes, it will determine materials’ properties

Metals• Copper (used for over 7,000 years initially as tools

and now as cables and heat conductors)

• Gold (used for over 7,000 years as jewelry, coins, and now cables and heat conductors)

• Silver (used for over 6,000 years as coins, jewelry, cables, medicine)

• Iron (used for over 3,000 years as tools and weapons)

• Aluminum (used for over 200 years: cables, rockets, airplanes, cans)

• Titanium (used for over 60 years: rockets, airplanes, marines, armor, consumer, etc)

time

Stone age(tools from stones,

wood, bones)

Bronze age(Copper-tin alloy produced

By melting Cu over fire: it

is harder & stronger than

pure Cu)

3300 BC 1200 BC

Iron age(harder and stronger

than bronze)

20th century

Si age(electronics)

???

Metals

Iron Gold

Common properties

• Mechanical: • Strong and tough, have high density

• Metals resist brittle fracture by bending - ductile

• Thermal: • Could be good thermal conductors (e.g. Cu, Au)

• Moderate temperature resistance (melting T: Al ̴ 660, Ag ̴ 900;

Au ̴ 1060, Cu ̴ 1080, Fe ̴ 1540, Ti ̴ 1670, and Mo ̴ 2625 ̊C)

• Electrical: • Structure has “free electrons” making metals good

electrical conductors

• Structural: • Atoms are located in regularly defined, repeating

positions - a crystal:

Metals

Ion cores of

2+ charge

Delocalized cloud

of valence electrons

• Part of the electrons are delocalized and shared by all the atoms, forming

a “cloud” or “sea” of “free” electrons

• Free electrons are responsible for high conductivity of metals

• Electron cloud shields positively charged atomic cores from each other

and repulsive forces do not develop during high impact stress, preventive

fractures and making metals ductile (will discuss later)

Ceramics • Sand

• Cements (used for over 8,000 years, now

believed that tops of Egyptian pyramids

were cast from cement)

• Clays (used for over 25,000 years

for sculpture, pottery, bricks, tiles)

• Glass (used for over 5,000 years)

• Thermal & electrical insulation

• Graphite

Common properties

• Mechanical: • Strong, have moderate density

• Ceramics bend little before they break - brittle

• Thermal: • Could have high (AlN) or low (ZrO2) thermal conductivity

• High temperature stability, chemically resistant

• Electrical: • Structure has no “free electrons” thus poor electrical

conductivity (used as insulators)

• Structural:

Ceramics

• Combination of metallic and non-metallic atoms

• Many but not all ceramics are crystalline:

SiO2: disordered

(glass) or ordered

(crystal) structure

Ceramics

• Ionic, covalent or mixed bonding

• The absence of free electrons make these materials good electrical

insulators

• Since all electrons are tightly bound, it is difficult to make new bonds

(thus good chemical resistance of ceramics)

• Due to tight bonds atoms are not free to move, making ceramics brittle

Polymers • Amber (mineralized resin, used for

over 6,000 years as jewelry)

• Latex (used for over 3,000 years by

Mayan who discovered methods for

treating natural rubber that were not

reproduced until 19th century; modern

use: over 200 years)

• Cellulose (wood fiber; used in paper and textiles)

• Polystyrene (used since 1931 for a variety of objects as fairly rigid,

economical plastic, as a foam it is used in virtually all meat and poultry trays)

• Nylon (used since 1939 for fishing line, toothbrush bristles, stockings, track

pants, shorts, swimwear, active wear, windbreakers, bedspread and draperies)

• Teflon (used since 1946 for coating on cookware, soil and stain repellant

for fabrics and textiles, chemical industries).

• Kevlar (used since 1965 for body armor, bicycles: five times stronger than

the same weight of steel)

Common properties

• Mechanical: • Low density

• Can be ductile or brittle

• Commonly relatively low strength

• Thermal: • Commonly low thermal conductivity

• Temperature sensitive

• Electrical: • Most polymers – electrical insulators;

• Structural:

Polymers

• Long chain molecules with repeating groups

• Easy to form into complex shapes

• Disordered or semi-crystalline

Structure of polyethylene. The

repeating unit is the -C2H4- group

Composites 2 or more materials are combined to achieve unique

combination of properties (e.g. rigidity, strength, and

low density)

• Adobe brick (straw is mixed with mud or clay, an adhesive with strong compressive

strength to achieve smaller and uniform more cracks in the clay, greatly improving the strength).

• Plywood (used for over 5500 years: thin slabs of wood held together by a strong

adhesive, making the structure stronger than just the wood itself)

• Carbon/Carbon (used for over 30 years: highly-ordered graphite fibers embedded in a

carbon matrix to achieve lightweight material with low thermal expansion coefficient, thus highly

resistant to thermal shock, or fracture due to rapid and extreme changes in temperature)

• Carbon/Epoxy (used for over 30 years: highly-ordered graphite fibers embedded in

epoxy dramatically improve its mechanical properties, including strength and toughness)

• Cermet (composite of ceramics and metal: high temperature electronic components,

resistors, capacitors)

McLAREN F1: all Carbon-Carbon composite car body structure

Semiconductors • Silicon (the 2nd most abundant element in the earth’s crust; used in semiconductor devices,

including integrated circuits)

• Germanium (in 1871 Dmitri Mendeleev predicted it to exist as a missing analogue to Si; the

element was discovered in 1886; originally used in transistor industry instead of Si; now

employed in infrared spectroscopes and other optical equipment which require extremely

sensitive infrared detector)

• GaAs (used in diodes incl. light-emitting diodes (LEDs), transistors, integrated circuits (ICs),

and analog devices such as oscillators and amplifiers)

• CdTe (used in solar cells, as an infrared optical material for optical windows and lenses)

• SiC (used in high temperature high power electronics, as substrates for nitrides growth, in

cutting tools, as abrasives, in jewelry)

• Bonding similar to ceramics

• Mechanical properties similar to ceramics

Representative strengths of the various material types

From: D. R. Askeland, The Science and Engineering of Materials

Correlation Between Strength and

DuctilityS

tre

ngth

Measure of Ductility

Correlation Between Strength and

DuctilityS

tre

ngth

Measure of Ductility

True improvement

in performance

Increase in Strength-to-Density Ratio over time

Committee on Materials Science and Engineering, Solid State Sciences Committee, Board on Physics and Astronomy, Commission on Physical Sciences, Mathematics, and Resources, and National Materials Advisory Board, Commission on Engineering and Technical Systems, National Resource Council. (1989). Materials science and engineering for the 1990s: maintaining competitiveness in the age of materials. Washington, DC: National Academy Press. Retrieved September 5, 2006, from http://www.nap.edu/books/0309039282/html/index.html

Increasing sophistication of human manipulation of materials

Structure-Property-Process

relationship

• Structure• Atomic / Nano / Micro / Macro

• Property• Mechanical

• Physical (electrical, magnetic, optical, thermal,

elastic, chemical)

• Process• Material history

The Periodic Table