Danyuo Yiporo (PhD inview)Materials Science Dept. of EEE, NTNU

08161243421yiporo@aol.com,

yiporodanyuo@gmail.com

Materials Science

Home Work must be submitted within or before the deadline given

Class participation is highly recommended Participation in exercise or group projects are

recommended No make-up exams for any student Midterm and final exams are only for students

who attended classes

Rules and Regulations for the Course

Teaching Strategies

The course will be taught via Lectures and Tutorial Sessions

The tutorial being designed to complement and enhance both the lectures and the students appreciation of the subject.

Course work assignments will be reviewed with the students.

Course Assessment

(i) Class Exercise: 5%(ii) Quizzes: 5 % (iii) Home Works/Group Project: 5 %(iv) Attendance: 5 % (v) One (1) mid-semester test, 1-hour duration counting

for 20% of the total course.(vi) (ii) One (1) End-of-semester examination, 2 hours

duration counting for 60% of the total course marks.

Course Content (i) Atomic and molecular structure, crystals, Metallic states,

Defects in crystals, conductors, semi-conductors and insulators. (ii) Alloy theory – Application to industrial alloys – steel in

particular. phases (iii) Engineering Properties – Their control, Hot and cold

working, heat treatment, etc. Creep, fatigue and fracture. Corrosion and corrosion control.

(iv) Non-metallic materials – glass, rubber, concrete, plastics, wood and ceramics.

(v) Elastic and plastic deformations: Defects in metals.

Books Materials Science Books Eg. Callister: Materials Science and Engineering by William D.

Callister, Jr. Chapter 1-9 Askeland

That’s easy! Look around. Our clothes are made of materials, our homes are

made of materials - mostly manufactured

Glass windows, electronics items, electrical appliances, metal silverware, ceramic dishes…

Most things are made from many different kinds of materials

What are Materials?

Defined as the study of the properties of solid materials and how those properties are determined by a material’s composition and structure

The ability to change the properties and/or behavior of a material is what makes most materials useful and this is at the heart of materials science!

Materials Science

Materials Science and Engineering

Defined as the study of the properties of solid materials and how those properties are determined by a material’s composition and structure

The ability to change the properties and/or behavior of a material is what makes most materials useful and this is at the heart of materials science!

An interdisciplinary study that combines metallurgy, physics, chemistry, biology, mathematics and engineering to solve real-world problems with real-world materials in an acceptable societal and economical manner

Materials Science and Engineering

The following elements and their interaction define Materials Science and Engineering: Performance Properties Structure and composition Synthesis and processing

Materials Science and Engineering

Classification of Materials

Metals Metals (Usually used as alloys between elements)(Usually used as alloys between elements)

CeramicsCeramics

1. The stone age2. The copper age3. The bronze age4. The iron age5. What would be a good material name for

today?

Submission date (17/03/2015) Room 128, 3rd seat

Home work 1: Write on the History of Materials according to;

(a) Briefly describe the 4 types of quantum numbers and what they represent.

(b)State the Pauli exclusion principle and what it means for the periodic table of elements.(c) Beryllium is a metallic element with atomic number 4. Briefly describe the atomic structure of Be, and write out the electronic configuration of beryllium in terms of its filled states.(d) What properties should the head of a carpenter’s hammer possess?Submission date (20/03/2015)

Room 128, 3rd seat

Home Work 2Atomic and Crystal Structure

A conductor is a material having a low resistance which allows electric current to flow in it. All metals are conductors and some examples include copper, aluminium, brass, platinum, silver, gold and carbon. Very little energy is required to promote electrons into the low-lying empty states. Generally, the energy provided by an electric field is sufficient to excite large numbers of electrons into these conducting states.

An insulator is a material having a high resistance which does not allow electric current to flow in it. Some examples of insulators include plastic, rubber, glass, porcelain, air, paper, cork, mica, ceramics and certain oils.

The key difference in insulators, conductors and semiconductors lies in the difference in bandgap energy. Metals have no or an overlap bandgap whereas insulators has a wider bandgap that doesn’t promote the easy flow of electrons into the conduction band.

Semiconductors on the other hand have their electrical properties mid-way between insulators and conductors. They have a narrow bandgap such that electrons could be excited from the valence band into the conduction band.

Increasing the temperature of either a semiconductor or an insulator results in an increase in the thermal energy that is available for electron excitation. Thus, more electrons are promoted into the conduction band, which gives rise to an enhanced conductivity. Examples of semiconductors are Silicon, Germanium, Indium Thin Oxide

Newer Branches of Materials ScienceNewer Branches of Materials Science• Nanotechnology: a relatively new area grown out

of techniques used to manufacture semiconductor circuits and controlled drug delivery systems

• Machines can be produced on a microscopic level – Example - miniature robots to do surgery inside the

body or miniature chemical laboratories and instruments that will continuously analyze blood and dispense medications inside the body.

– Nanodrug formulations for disease detection and treatment

Materials TestingMaterials Testing• Materials testing is a much narrower field

than materials science or engineering• It is a way to determine the strength of

certain materials• It is mostly used to determine safety. Ex.

concrete samples are tested• It is not used to design new materials to be

used in new applications

History of MaterialsHistory of Materials

• Man has been studying materials since before leaving the cave.

• Due to lack of communication, early man spent hundreds of millennia experimenting with stone tools.

• The first metal tools appeared perhaps only six thousand years ago.

History of MaterialsHistory of Materials• The discovery of “Iceman” in the Alps (btn France and

Austria) in 1991 gave significant information on early Copper age. He was carrying a copper axe.

• It is dated at about 5300 years, when the first pyramids were built.

• As our knowledge of materials grows, so does the sophistication of our tools.

• The more sophisticated our tools, the more sophisticated our accomplishments

F.Nimmo EART162 Spring 10

Atomic Description• Atoms have a (Boltzmann)

distribution of kinetic energies• The distribution is skewed –

there is a long tail of high-energy atoms Energy E

No.

of p

artic

les Peak = kT/2

Mean= 3kT/2

• The fraction of atoms with a kinetic energy greater than a particular value E0 is:

)/exp(2)( 00

0 kTEkTEEf

• If E0 is the binding energy, then f is the fraction of atoms able to move about in the lattice and promote flow of the material

• So flow is very temperature-sensitive

Quantum NumbersQuantum Numbers

2n3

Bonding Between AtomsBonding Between Atoms

• Forces between atoms are like little springs:

• Determines macroscopic properties– Melting Temperature– Thermal Expansion Coefficient– Elastic (Young’s) Modulus

• The coefficient of elasticity of a solid; the rate of change of stress with strain

• N.B. These are fundamental properties which are not altered by processing

Interatomic Bonding and Melting PointInteratomic Bonding and Melting Point

• Types of bonds:• Ionic bonding:

– Forms between a metal and non-metal

– Horizontal extremes of the periodic table

– Egs are NaCl, CsCl, MgO, CaF2

Ionic bonding:

Bonding and Interatomic ForcesBonding and Interatomic Forces