Docsity
Docsity

Prepare for your exams
Prepare for your exams

Study with the several resources on Docsity


Earn points to download
Earn points to download

Earn points by helping other students or get them with a premium plan


Guidelines and tips
Guidelines and tips

Materials for Engineering - Material Science for Engineers - Lecture Slides, Slides of Material Engineering

These are the Lecture Slides of Material Science for Engineers which includes Structure of Wood, Moisture Content, Density of Wood, Mechanical Properties of Wood, Expansion and Contraction of Wood, Concrete Materials, Properties of Concrete etc. Key important points are: Materials for Engineering, Materials Science, Organization of Atoms, Electrons and Nuclei, Structure of Steel, Materials Selection Process, Crystal Structure, Electrical Resistivity of Copper

Typology: Slides

2012/2013

Uploaded on 03/21/2013

dharuna
dharuna 🇮🇳

4.7

(6)

87 documents

1 / 24

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
Chapter 1 Materials for Engineering
A fly-by during deployment of the aircraft carrier USS
Stennis. The pilot was grounded for 30 days, but he
likes the picture and thinks it was worth it.
Docsity.com
pf3
pf4
pf5
pf8
pf9
pfa
pfd
pfe
pff
pf12
pf13
pf14
pf15
pf16
pf17
pf18

Partial preview of the text

Download Materials for Engineering - Material Science for Engineers - Lecture Slides and more Slides Material Engineering in PDF only on Docsity!

Chapter 1 Materials for Engineering

A fly-by during deployment of the aircraft carrier USSStennis. The pilot was grounded for 30 days, but helikes the picture and thinks it was worth it.

Materials Science and

Engineering

• Materials Science – Investigating

relationships that exist between the structureand properties of materials

• Materials Engineering – Is, on the basis of

these structure-property correlations,designing or engineering the structure of amaterial to produce a pre-determined set ofproperties

Terminology

mil = 1 / 1000 inch = 25.4 μm

micrometer = 1 / 1,000,000 meter = 1μm

Angstrom = 1 / 10,000,000,000 meter = 1Å

1 MICROMETER IS TWO WAVELENGTHS OF GREEN LIGHT LONG

A HAIR IS 100 MICROMETERS

A 1 MICRON WIDE LINE ON A CD

IS THE SAME SCALE AS A 100 FOOTWIDE ROAD ON NORTH AMERICA

Progress in atomic-level understanding

DNA ~2 nm wide

Things Natural
Things Manmade

THE SCALE OF THINGS

(^10) nm

Cell membrane

ATP synthase

Schematic, central core

Cat ~ 0.3 m

Dust mite^300

μ

m

Monarch butterfly

~ 0.1 m

MEMS (MicroElectroMechanical Systems) Devices

10 -

μm wide^ Red blood cellsPollen grain

Fly ash ~ 10-

μm

Bee ~ 15 mm

Atoms of silicon spacing ~tenths of nm

Head of a pin

1-2 mm

Magnetic domains garnet

film 11

μm widestripes

Progress in miniaturization

Indium arsenidequantum dot

Quantum dot array -- germanium dots on silicon Microelectronics Objects fashioned from

metals, ceramics, glasses, polymers ...

Human hair ~ 50

μm wide

The

Microworld

0.01 1 nanometer (nm) 0.1 nm

μ m 0.1 10 nm

μ m 1 micrometer (100 nm

μ m)

0.01 mm 10

μ m 0.1 mm 100

μ m 1 meter (m)0.1 m100 mm0.01 m1 cm10 mm 1 millimeter (mm)

10

0 m 10

-1^ m 10

-2^ m 10

-3^ m 10

-4^ m 10

-5^ m 10

-6^ m 10

-7^ m 10

-8^ m 10

-9^ m 10

-^

m

Visiblespectrum

The

Nanoworld

The 21st century challenge -- Fashion materials at the nanoscale with desired properties and functionality

Red blood cellswith white cell

~ 2-

μ

m

Docsity.com

ex: hardness vs structure of steel

  • Properties depend on structure
Data obtained from Figs. 10.21(a)and 10.23 with 4wt%C composition,and from Fig. 11.13 and associateddiscussion,

Callister 6e.

Micrographs adapted from (a) Fig.10.10; (b) Fig. 9.27;(c) Fig. 10.24;and (d) Fig. 10.12,

Callister 6e.

ex: structure vs cooling rate of steel

Structure, Processing, & Properties• Processing can change structure

Cooling Rate (C/s)

600500400300200100

1

10

100

1000

(a)

m

(b)

m

(d)

m

(c)

m

Hardness (BHN)

Pick Application

Determine required Properties

Properties

Identify candidate Material(s)

Material

Identify required Processing

Processing: changes

structure and overall

shape

ex: casting, sintering, vapor deposition, doping

forming, joining, annealing.

Properties: mechanical, electrical, thermal,magnetic, optical, deteriorative.Material: structure, composition.

The Materials Selection Process

T (°C)

Cu + 3.32 at%Ni

Cu + 2.16 at%Ni

deformed Cu + 1.12 at%Ni

ρ Resistivity,

Ohm-m)-8 (

Cu + 1.12 at%Ni

“Pure” Cu

• Electrical Resistivity of Copper:• Adding “impurity” atoms to Cu increases resistivity.• Deforming Cu increases resistivity.

Adapted from Fig. 18.8,

Callister 6e.

(Fig. 18.8 adapted from: J.O. Linde,Ann Physik 5, 219 (1932); andC.A. Wert and R.M. Thomson,Physics of Solids, 2nd edition,McGraw-Hill Company, New York,1970.)

ELECTRICAL

Magnetic Permeabilityvs. Composition:--Adding 3 atomic % Si

makes Fe a betterrecording medium!

Magnetic Field

Magnetization

Fe+3%Si

Fe

Adapted from C.R. Barrett, W.D. Nix, andA.S. Tetelman,

The Principles of

Engineering Materials, Fig. 1-7(a), p. 9,1973. Electronically reproducedby permission of Pearson Education, Inc.,Upper Saddle River, New Jersey.

Fig. 20.18,

Callister 6e.

(Fig. 20.18 is from J.U. Lemke,

MRS Bulletin,

Vol. XV, No. 3, p. 31, 1990.)

• Magnetic Storage:

--Recording medium

is magnetized byrecording head.

MAGNETIC

• Stress & Saltwater...

--causes cracks!

• Heat treatment:

slows

crack speed in salt water!

m

--material:

7150-T651 Al "alloy"(Zn,Cu,Mg,Zr)

Adapted from Fig. 11.20(b), R.W. Hertzberg, "Deformation andFracture Mechanics of Engineering Materials" (4th ed.), p. 505,John Wiley and Sons, 1996. (Original source: Markus O.Speidel, Brown Boveri Co.)
Adapted from Fig. 17.0,

Callister 6e.

(Fig. 17.0 is from

Marine Corrosion, Causes,

and Prevention, John Wiley and Sons, Inc.,1975.)

Adapted from Fig. 11.24,Callister 6e. (Fig. 11.24 provided courtesy of G.H.Narayanan and A.G. Miller, Boeing CommercialAirplane Company.)

“held at160C for 1hrbefore testing”

increasing load

crack speed (m/s)

“as-is”

10 -8 10 -

Alloy 7178 tested insaturated aqueous NaClsolution at 23C

DETERIORATIVE

Types of Materials

Metals: strong, ductile, tough, high density, conductors.Ceramics: strong, brittle, low density, insulators.Polymers: weak, ductile, low density, insulators.Semiconductors: weak, brittle, low density, semi-conductors.Composites: strong, ductile, low density, conductors, insulators. Crystals: atoms have long range periodic order (a).Glasses: atoms have short range order only (b).

(a)

(b)

Several uses of steel and pressed aluminum.

Metals

Examples of ceramic materials ranging from household and labproducts to high performance combustion engines which utilize bothMetals and ceramics.

Ceramics

Examples of glasses. Depending on the material structure, the glasscan be opaque, transparent, or translucent. Glasses can also beProcessed to yield high thermal shock resistance.

Ceramics

Polymers or commercially called “Plastics” need no intro.

Polymers