BBM 10103 material technology

7/24/2019 BBM 10103 material technology

http://slidepdf.com/reader/full/bbm-10103-material-technology 1/34

#Mr. Muhammad Azri Bin Othman#BBM 10103# Pemilihan Bahan# SEM1 SESI 2013/2014#

CHAPTER 1:

INTRODUCTION



Introduction to material science and

engineering • Materials science and engineering is an multidisciplinary field

concerned with inventing new materials and improve previously

known materials by developing a deeper understanding of the

microstructure-composition-synthesis-processing relation ship.

• Material Science:-

The emphasis is on underlying relationship between the synthesis and

processing. Structure and properties of material.

• Material Engineering:-

The focus is on how to translate or transform materials to useful device

or structure.




The modern materials scientist plays three major roles in the

development of technology

1) Material Selection

In order to produce working machines from engineering design, each

part of the machine must fill a number of criteria, for example high

strength, high ductility, good electrical properties, low weight, orlow cost. The materials scientist responsible for recommending

materials to best fit these criteria

2) Materials research

The materials scientist determines the strength, wear resistance, and

other properties of materials as well as studying the microscopic,

electronic and atomic structures that give rise to these properties.

This enable both proper use of materials by engineers as well as the

possibility of designing new materials to fulfill specific needs




• Materials development

By applying the knowledge gained by studying the structure of

materials, the materials scientist can design materials with

specific properties by varying composition and processing.

Such work often results in materials which can be used in

applications that would have been impossible before.




Generic Product development flow

diagram




6

Function

Material Shape

Process

Material selection and process cannot be separated from the shape and the

function of the product, two way interaction.

Function dictates the choice of

material and shape.

Process interacts withshape.

Process is influenced bymaterial

Shape restricts the

choice of material

and process.


Factors that influences the material

selection process


http://slidepdf.com/reader/full/bbm-10103-material-technology 7/34#Mr. Muhammad Azri Bin Othman#BBM 10103# Pemilihan Bahan# SEM1 SESI 2013/2014#

Mater ials Properties

Mechanical Physical Chemical Optical

Material Properties

Properties are the way the material responds to the environmentand external forces.



Mechanical Properties

Deformation and fracture as a response to applied

mechanical forces

•

Strength•Hardness

•Ductility

•Stiffness




Physical Properties (Thermal)

Affected by heat fluxes and temperature changes

•Thermal Capacity – Heat storage capacity of a

material

•Thermal Conductivity

–

Capacity of a material totransport heat

•Thermal Expansion – How a material expands or

contracts if the temperature is raised or lowered




Physical Properties (Electrical)

Material response to electromagnetic fields

•Electrical Conductivity – Insulators, dielectrics,

semiconductors, semimetals, conductors,superconductors

•Thermoelectric – Electrical stimuli provoke thermo

responses; thermo stimuli provoke electrical responses




Chemical Properties

Response and impact of environment on material

structures

•

Oxidation and Reduction –

Occur in corrosion andcombustion

•Toxicity – The damaging effect a material has on other

materials

• Flammability –

The ability of a material to ignite and

combust




Example

Material

Properties



13

Engineering Materials Classification

Composi tes


Materials

Metals Plast ics Ceramics

Glass



14

Materials

Metals Plastics

Steel

Stainless steel

Die & tool steel

Cast iron

Ferrous Non-ferrous

Aluminum

Copper

Zinc

Titanium

Tungsten

Thermoplast ics

Acrylic

Nylon

ABS

Polyethylene

Polycarbonate

PVC

Thermosets

Phenolic

Polymide

Epoxies

Polyester

Elastomers

Rubber

Polyurethane

Silicone


Materials Classification Con’t



15

Materials

Metals PlasticsCeramics

Glass

Carbides

Nitrides

Graphite

Diamond

Glasses

Glass ceramics

Composi tes

Reinforced

plastics

Metal-Matrix

Ceramic-Matrix

Laminates


Materials Classification Con’t



16

Major characteristics of metallic materials are crystalline,conductivity to heat and electricity and relatively high strength& toughness.

Classification: systematic arrangement or division of materials into

group on the basis of some common characteristicGenerally classified as ferrous and nonferrous

• Ferrous materials-iron as the base metal,

range from plain carbon (>98% Fe) to high alloy steel

(<50% alloying elements)

• Nonferrous materials consist of the rest of the metalsand alloys

Eg. Aluminum, magnesium, titanium & their alloys

Classifications & Specifications of MetallicMaterials



17

Within each group of alloy, classification can be madeaccording

(a) chemical composition, e.g. carbon content or alloyscontent in steels;

(b) finished method, e.g. hot rolled or cold rolled;

(c) product form, e.g. bar, plate, sheet, tubing, structuralshape;

(d) method of production, e.g. cast, wrought alloys.




18

In most eng. application, selection of metallic is usually based on thefollowing considerations:

1) Product shape: a) sheet, strip, plate, (b) bar, rod, wire, (c)tubes, (d) forging (e) casting

2) Mechanical properties-tensile, fatigue, hardness, creep,impact

test3) Physical & chemical properties-specific gravity, thermal &

electrical conductivity, thermal expansion

4) Metallurgical consideration-anisotrophy of properties,

hardenability of steel, grain size & consistency of properties5) Processing castability-castability, formability, machinability

6) Sales appeal-color, luster

7) Cost & availability




19

• Polymer –

low density, good thermal & electrical insulation,high resistance to most chemicals and ability to take colours

and opacities.

• But unreinforced bulk polymer are mechanically weaker,

lower elastic moduli & high thermal expansion coefficients.

• Improvement Reinforced variety of fibrous materials

Composites (PMC).


Classifications & Specifications of Polymers



20

• Advantages : ease of manufacturing & versatility.

Can manufacture into complicated shapes in one stepwith little need for further processing or surface

treatment.

Versatility : ability to produce accurate component, with

excellent surface finish and attractive color, at low costand high speed

• Application: automotive, electrical & electronic products,

household appliance, toys, container, packaging, textiles

• Basic manufacturing processes for polymer parts are

extrusion, molding, casting and forming of sheet.




21

• Thermoset & thermoplastic

Differ in the degree of their inter-molecular bonding Thermoplastic-litle cross bonding between polymer,

soften when heated & harden when cooled

Thermoset-strong intermolecular bonding which

prevents fully cured materials from softening when

heated

• Rubber are similar to plastic in structure and the difference

is largely based on the degree of extensibility or stretching.




22

• Ceramics – inorganic compounds of one or more metals with a

nonmetallic element. Eg Al2O3, SiC, Si2 N3.

o Crystal structure of ceramic are complex

They accommodate more than one element of widelydifferent atomic size.

o The interatomic forces generally alternate between ionic &covalent which leave few free electrons

usually heat & electrical insulators.o Strong ionic & covalent bonds give high hardness, stiffness

& stability (thermal & hostile env.).


Classifications & Specifications of Ceramic



23

• Structure:

(1) Amorphous or glass-short range order, (2) crystalline(long range order) & (3) crystalline material bonded byglassy matrix.

• Clasiification:

Whitewares, glass, refractories, structural clay products& enamels.

• Characteristics:

Hard & brittleness,

low mechanical & thermal shock

High melting points

Thermal conductivities between metal & polymer




24

Design consideration for ceramics

• Britle, low mechanical & thermal shock-need special

consideration

• Ratio between tensile strength, modulus of rupture &compressive strength ~ 1:2:10. In design, load ceramic parts incompression & avoid tensile loading

• Sensitive to stress concentration Avoid stress raiser during design.

• Dimensional change take place during drying and firing, should be consider

• Large flat surface can cause wrapping• Large changes in thickness of product can lead to nonuniform

drying and cracking.

• Dimensional tolerances should be generous to avoid machining




25


Classifications & Specifications of Composites

• Can be any type of mixture: polymer+metal, polymer+glass,metal+ceramic, ceramic+ceramic



26


Characteristics of Composites



27

Design consideration for composites• Consider special characteristics and properties of

composites (why do you prefer them in the product?)• Composites combine the properties of different

materials and generate new properties• For example glass fibers are strong but brittle;

polymers are much tougher. A glass fiber reinforcedpolymer is both tough and strong.

• For conventional materials, the designer may consult ahandbook or manual to obtain a certain property

(strength, hardness, thermal conductivity- etc.)• For composite materials, the designer has to consult

“performance charts” or “carpet plots” representing aparticular property of a given composite system


Application of Most Commonly Used Materials



Ken Youssefi SJSU, ME dept. 28

Component Material



Application of Most Commonly Used Material




Application of Most Commonly Used Material

Component Material







Component Material




Application of composite materials in

Boeing 757-200


Source: Courtesy of Boeing Commercial Airplane Company




Example :Research impacts products (Nokia)

Power management

Battery life, charging,thermal durability

MaterialsStructural, functional,

optical, decorative

Cameras and optics

ElectronicsSemiconductors,

microelectromechanical

componentsAlgorithms

Signal processing, image and

sound processing

ProximityWLAN, Ultra Wideband,

RFID, Bluetooth

Voice & Video codecsImproved quality

Software and

ApplicationsPlatforms, middleware,

architectures

GSM/WCDMAStrong IPR portfolio

User experience

Ergonomy, usability, userinterfaces, user behavior,

security

MechanicsStructures, user interface,

mechanisms



33 © 2005 Nokia YN10.10.2006

Materials research in products

Nokia 5140

• Integrated soft-hard

cover

Nokia N90

• Materials for

transformable

mechanics

• High strength &

accuracy, low friction

Nokia 7280

• laser patterned

decoration• half-mirror window

• thin rotator plate




Multi-disciplinary research needed

Need research in multi-disciplinary areas• Materials technology• Novel manufacturing

technologies• Examples:

• Flexible/Printed

electronics• Nanotechnology

Drivers for futurecommunication devices • Enhanced user experience,

new features/functions,design look & feel

• Small, compact, easy touse, easy to carry/wear

• Integration of electronics

and mechanics forfunctionality andproduction

Documents

BBM 10103 material technology