ITB (Institut Teknologi Brunei) Engineering Materials Introduction PCE1ENM 2013

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Before we begin……..DGH needed a crown

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• Get into groups of 3-4 students and think:

What properties does DGH require in the

material used for his crown?

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Chapter 1 -

A tooth “fit for a lecturer”

Properties:

Water proof

Resistant to chemical attack

Durable for duration of human lifespan

Surface feel same as a normal tooth

As “ard” as a tooth

Tastes like a tooth

Smells like a tooth

Doesn’t attract “stuff” onto its surface

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Engineering Materials

Course Objective...

Introduces fundamental concepts in MaterialsScience and Engineering

You will learn about:• material properties / structure

• how properties dictate structure

• how processing can change structure

This course will help you to:• use/design materials properly

• realise new design opportunities with materials

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LECTURES

Lecturer: David Hassell

Time (during Ramadan):

Wed 09:45 – 11:00 and Thurs 11:00 – 12:00

Activities:

• Present new materials/lecture notes

• Lectures/ Example classes

• Group work and discussions

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ASSESSMENT

Degree[PCE1ENM]

Higher Diploma[PCE1ENH]

In-class test 10 10

Report 10 20

Assessed

exercises

10 10

Exam 70 60

Coursework will be mainly the same, but marked

differently.

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Chapter 1 - Introduction to Materials Science and Engineering

• What is materials science/eng?

• Why should we know about it?

• Materials drive our society

– Stone Age

– Bronze Age

– Iron Age

• Now?

– Silicon Age?

– Polymer Age?

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Student exercise:

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Split into groups of 4:

Task: Think of the products and materials that we use today. List down ten items that we use regularly today (2013) that we didn’t 10 years ago (2003).

We’ll then go through the list of each group and see what products are everyday items

Q: What materials make these products possible? Are they new, or are they old materials?

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Chapter 1 -

Student exercise:

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Facebook

Opic fibre cables for phone/internet

Clever phone

“A* grade” television

Thunderbolt

Digital camera

James Bond style camera contact lens

Google everything!

3D cinema glasses

e-cigar

Hybrid (ugly) car

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Examples cont….:

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3D printer

Blue ray DVD’s & “stuff”

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Age Period Tools

Stone

age

Palaeolithic Handmade tools and objects found in nature –

cudgel, club, sharpened stone, chopper,

handaxe, scraper, spear, harpoon, needle,

scratch awl

Mesolithic

(other name

epipalaeolithic)

Handmade tools and objects found in nature –

bow and arrow, fish – basket, boats

Neolithic Handmade tools and objects found in nature –

chisel, hoe, plough, yoke, reaping-hook,

grain pourer, barley, loom, earthenware

(pottery) and weapons

Bronze Age Copper and bronze tools, potter's wheel

Iron Age Iron tools

Historical Perspective

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Materials Science vs Engineering

Materials science – investigating the relationships that exist between the structures and properties of materials

Materials engineering – designing or engineering the structure of a material to produce a pre-determined set of properties

Material scientist - develops/synthesizes new materials

Material engineer – creates new products/systems using existing materials and/or develops techniques for processing materials

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Material Structures

• Structure relates to the arrangement of its internal components

• Subatomic structure - electrons, protons and neutrons

• Atomic structure - encompasses the organisation of atoms or molecules relative to one another

• Microscopic structure - large groups of atoms that are normally agglomerated together, that can be viewed under the microscope.

• Macroscopic structures – very large groups of atoms that can be viewed by the naked eye

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Material Properties

1. Mechanical – elastic modulus, strength

2. Electrical – electrical conductivity, constants

3. Thermal – thermal conductivity, heat capacity

4. Magnetic – response of a material in a

magnetic field

5. Optical – refractive index, reflective index

6. Deteriorative – chemical reactivity

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Material Processing and Performance

Aluminum oxide may be transparent, translucent, oropaque depending on

the material structure.

single crystalpolycrystal:low porosity

polycrystal:high porosity

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Why study Materials Sc/Eng?

• Important in the investigation and design

of materials

• Selecting the right material for an

application

• Economics of material selection and

utilisation

• Basically, an engineer with the above

knowledge would be one who is proficient

and confident when making selection or

designing materials

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Types of Materials

• Metals:

– 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, elastic

– non-conducting (insulators)

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1. Metals

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2. Polymers/Plastics

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3. Ceramics

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Beverage containers:

what are adv and disadv of each?

Aluminium cans

Plastic bottles

Glass bottles

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Beverages – why la?

• Plastic fantastic

• Cheap, light, can

be

reused/recycled,

ductile,

transparent, inert?

• Mundane Metal

• Cheap (ish),

recyled, light,

ductile, shiny, inert

• Gorgeous glass

• Expensive

(relatively), heavy,

inert, brittle,

recyled

(elsewhere), cool22

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Advanced Materials

Advanced materials – materials used in high or advanced technological applications

What do we mean by high technology?

A device or product that operates / functions using relatively intricate and sophisticated principles

Examples?

Electronic equipment (camcorders, CD/DVD players, etc), computers, fibre-optic systems, spacecraft, military, rocketery, etc

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Classification of Advanced Materials

1. Semiconductors

2. Biomaterials

3. Smart materials

4. Nano-engineered materials

3 and 4 are known as “materials of the

future”

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1. Semiconductors

• Electrical properties that are intermediate

between the electrical conductors and the

insulators

• Example semiconductor materials – silicon,

germanium

• They are extremely sensitive with the

presence of impurities, even at minute

concentrations (doping)

• Semiconductors have totally revolutionised

the electronics and computer industry

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2. Biomaterials

• Employed in components planted into the

human body for replacement of diseased or

damaged body parts

• These materials must not produce toxic

substances and must be compatible with

body tissues

• All the basic materials – metals, ceramics,

polymers, composites, etc may be used as

biomaterials

• Following is an example of biomaterial

utilisation in artificial hip replacements

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Example – Hip Implant

• With age or certain illnesses joints deteriorate.

Particularly those with large loads (such as hip).

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Hip Implant

• Requirements

– mechanical

strength (many

cycles)

– good lubricity

– biocompatibility

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Hip Implant

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Hip Implant

• Key problems to overcome

– fixation agent to hold

acetabular cup

– cup lubrication material

– femoral stem – fixing agent

(“glue”)

– must avoid any debris in cup

Femoral

Stem

Ball

Acetabular

Cup and Liner

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3. Smart materials

• Smart/ Intelligent materials – group of new state-of-the-art materials

• Are able to sense changes in their environments and then respond to these changes in pre-determined manners (traits that are found in living organisms)

• Components of smart materials –traditional materials (metals, ceramics, polymers) + sensors (piezoelectric ceramics, magnetostrictive materials and electrorheological/magnetorheological fluids, etc)

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Example – Helicopters

• A smart material which can reduce aerodynamic cockpit noise that is created by the rotating rotor blades

• Piezoelectric sensors inserted into the blades monitor stresses and deformations; feedback signals from these sensors are fed to a computer-controlled adaptive device, which generates noise-canceling anti-noise

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4. Nano-engineered materials

• Materials which are produced by

arranging individual atoms (at the nano

level) – provides us with the opportunity

to design new materials, with new

mechanical, electrical, magnetic and

other properties

• A “bottom-up” approach

• One important material – the carbon

nanotube

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Example – Carbon Nanotubes

3D model of three types

of single-walled carbon

nanotubes.

This animation of a

rotating Carbon

nanotube shows its

3D structure.

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1. Pick Application Determine required Properties

2. Properties Identify candidate Material(s)

3. Material Identify required Processing

Processing: changes structure and overall shape

ex: casting, sintering, vapor deposition, dopingforming, joining, annealing.

Properties: mechanical, electrical, thermal,magnetic, optical, deteriorative.

Material: structure, composition.

The Materials Selection Process