UNIT 1-LN the Materials and Process Universe

The CES EduPackThe CES EduPackUniversity of University of CambridgeCambridge

© MFA 2009

Mike Ashby , Cambridge, UK, 2009

Unit 1. The materials and processes universe:families, classes, members and attributes

© MFA 2009

The expansion of the materials world

James Stuart, Professor of Engineering at Cambridge

1875 - 1890

No polymers – now over 45,000

• Today: > 160,000 engineering materials

No light alloys – now several thousand

No composites – now hundreds ……

• In his day: a few hundred materials

© MFA 2009

Outline

Resources:

• “Materials: engineering, science, processing and design” by M.F. Ashby, H.R. Shercliff and D. Cebon, Butterworth Heinemann, Oxford 2007, Chapters 1 and 2

• “Materials Selection in Mechanical Design”, 3rd edition by M.F. Ashby,

Butterworth Heinemann, Oxford, 2006, Chapters 1 - 3.

• Callister, Budinski, Askeland and others – recommended reading in records

• CES EduPack 2009 software ( Grantadesign.com)

Resources:

• “Materials: engineering, science, processing and design” by M.F. Ashby, H.R. Shercliff and D. Cebon, Butterworth Heinemann, Oxford 2007, Chapters 1 and 2

• “Materials Selection in Mechanical Design”, 3rd edition by M.F. Ashby,

Butterworth Heinemann, Oxford, 2006, Chapters 1 - 3.

• Callister, Budinski, Askeland and others – recommended reading in records

• CES EduPack 2009 software ( Grantadesign.com)

• Background: the motivation

• Materials and their attributes

• The CES EduPack and its use

• Hands-on session 1, with exercises

© MFA 2009

Teaching materials to engineering students

Engineers make things. They make them out of materials, using processes.

The starting point

The CES EduPack provides the resources to achieve this and gives students a tool they can use in their later profession (like CAD or FE tools)

What do they need to know to do this successfully?

• A perspective of the world of materials and processes

An ability to select those that best meet requirements of a design

Access to information and tools for comparison and selection

An understanding material properties and their origins

© MFA 2009

Mechanical engineering

Ceramics,glasses

Hybrids, composites

Polymers,elastomers

Metals,alloys

© MFA 2009

Aerospace and motorsport

Hybrids, composites

Polymers,elastomers

Metals,alloys

Ceramics,glasses

© MFA 2009

Civil engineering and architecture

Hybrids, composites

Polymers,elastomers

Metals,alloys

Ceramics,glasses

© MFA 2009

Bio-engineering

Ceramics,glasses

Polymers,elastomers

Metals,alloys

Hybrids, composites

© MFA 2009

Product & industrial design

Hybrids, composites

Polymers,elastomers

Metals,alloys

Ceramics,glasses

© MFA 2009

The database

Links

Suppliersdata-table

Referencesdata-table

Links

Organizing information: the CES Edu database

Materials

data-table

DATA FOR

Metals & alloys

Polymers

Ceramics & glasses

Hybrids

Processesdata-table

DATA FOR

Joining

Shaping

Surface treatment

Select on material properties

Select on links

Select on process properties

© MFA 2009

Organising information: the MATERIALS TREE

Universe

Materialsdata-table

Family

• Ceramics& glasses

• Metals & alloys

• Polymers & elastomers

• Hybrids

Structured

information

Unstructured

information

Class

Steels

Cu-alloys

Al-alloys

Ti-alloys

Ni-alloys

Zn-alloys

Member

1000

2000300040005000600070008000

Material records

Attributes

Al 6463

Density

Mechanical props.

Thermal props.

Electrical props.

Optical props.

Corrosion props.

Documentation

-- specific

-- general

Al 6463

Density

Mechanical props.

Thermal props.

Electrical props.

Optical props.

Corrosion props.

Documentation

-- specific

-- general

Al 6060

Density

Mechanical props.

Thermal props.

Electrical props.

Optical props.

Corrosion props.

Documentation

-- specific

-- general

Al 6060

Density

Mechanical props.

Thermal props.

Electrical props.

Optical props.

Corrosion props.

Documentation

-- specific

-- general

Al 6061

Density

Mechanical props.

Thermal props.

Electrical props.

Optical props.

Corrosion props.

Documentation

-- specific

-- general

Al 6061

Density

Mechanical props.

Thermal props.

Electrical props.

Optical props.

Corrosion props.

Documentation

-- specific

-- general

© MFA 2009

Structured information for ABS*

General PropertiesDensity 1.05 - 1.07 Mg/m^3Price 2.1 - 2.3 US $/kg

Mechanical PropertiesYoung's modulus 1.1 - 2.9 GPaYield strength 18 - 50 MPaTensile strength 27 - 55 MPaElongation 6 - 8 %Hardness - Vickers 6 - 15 HVFatigue strength 11 - 22 MPaFracture toughness 1.2 - 4.2 MPa.m1/2

Thermal PropertiesMax Service temp 350 - 370 KThermal expansion 70 - 75 10-6/KSpecific heat 1500 - 1510 J/kg.KThermal conductivity 0.17 - 0.24 W/m.K

Acrylonitrile-butadiene-styrene (ABS) - (CH2-CH-C6H4)n

Electrical PropertiesConductor or insulator? Good insulator

Optical PropertiesTransparent or opaque? Opaque

Corrosion and Wear ResistanceFlammability AverageFresh water GoodOrganic solvents AverageOxidation at 500C Very PoorSea water GoodStrong acid GoodStrong alkalis GoodUV Good

*Using the CES Level 2 DB

+ Links to Processes

© MFA 2009

Unstructured information for ABS*

What is it? ABS (Acrylonitrile-butadiene-styrene ) is tough, resilient, and easily molded. It is usually opaque, although some grades can now be transparent, and it can be given vivid colors. ABS-PVC alloys are tougher than standard ABS and, in self-extinguishing

grades, are used for the casings of power tools. Design guidelines. ABS has the highest impact resistance of all polymers. It takes color well. Integral metallics are possible (as in GE Plastics' Magix.) ABS is UV resistant for outdoor application if stabilizers are added. It is hygroscopic (may need to be oven dried before thermoforming) and can be damaged by petroleum-based machining oils.

ABS can be extruded, compression moulded or formed to sheet that is then vacuum thermo-formed. It can be joined by ultrasonic or hot-plate welding, or bonded with polyester, epoxy, isocyanate or nitrile-phenolic adhesives.

Technical notes. ABS is a terpolymer - one made by copolymerising 3 monomers: acrylonitrile, butadiene and syrene. The acrylonitrile gives thermal and chemical resistance, rubber-like butadiene gives ductility and strength, the styrene gives a glossy surface, ease of machining and a lower cost. In ASA, the butadiene component (which gives poor UV resistance) is replaced by an acrylic ester. Without the addition of butyl, ABS becomes, SAN - a similar material with lower impact resistance or toughness. It is the stiffest of the thermoplastics and has excellent resistance to acids, alkalis, salts and many solvents.

Typical Uses. Safety helmets; camper tops; automotive instrument panels and other interior components; pipe fittings; home-security devices and housings for small appliances; communications equipment; business machines; plumbing hardware; automobile grilles; wheel covers; mirror housings; refrigerator liners; luggage shells; tote trays; mower shrouds; boat hulls; large components for recreational vehicles; weather seals; glass beading; refrigerator breaker strips; conduit; pipe for drain-waste-vent (DWV) systems.

The environment. The acrylonitrile monomer is nasty stuff, almost as poisonous as cyanide. Once polymerized with styrene it

becomes harmless. ABS is FDA compliant, can be recycled, and can be incinerated to recover the energy it contains. *Using the CES Level 2 DB

© MFA 2009

The world of manufacturing processes

Joining

Welding

Primaryshaping

Heater Screw

Granular PolymerMould

Nozzle

Cylinder

No.8-CMYK-5/01

Injection moulding

Secondaryshaping

Machining

Surface treating

Painting

© MFA 2009

Organising information: the PROCESS TREE

Universe

Processesdata-table

Family

Joining

Shaping

Surfacing

Class

Casting

Deformation

Moulding

Composite

Powder

Rapid prototyping

Member

Compression

Rotation

Injection

RTM

Blow

Attributes

Process records

RTM

Material

Shape

Size Range

Min. section

Tolerance

Roughness

Economic batch

Documentation

-- specific

-- general

RTM

Material

Shape

Size Range

Min. section

Tolerance

Roughness

Economic batch

Documentation

-- specific

-- general

Blow molding

Material

Shape

Size Range

Min. section

Tolerance

Roughness

Economic batch

Documentation

-- specific

-- general

Blow molding

Material

Shape

Size Range

Min. section

Tolerance

Roughness

Economic batch

Documentation

-- specific

-- general

Injection molding

Material

Shape

Size Range

Min. section

Tolerance

Roughness

Economic batch

Documentation

-- specific

-- general

Injection molding

Material

Shape

Size Range

Min. section

Tolerance

Roughness

Economic batch

Documentation

-- specific

-- general

Structured

information

Unstructured

information

© MFA 2009

The CES EduPack

Advanced text Industrial design text Elementary text

Software

Eco text

The CES EduPackThe CES EduPackUniversity of University of CambridgeCambridge

© MF A 2009

Mike Ashby , Cambridge, UK, 2009

Unit 1. The materials and processes universe:families, classes, members and attributes

PowerPoint lectures White papers

© MFA 2009

Materials science

Polymer engineering

Eco-audit and design

Architecture & civil eng

Aeronautical engineering

Natural and biomaterials

The CES EduPack 09

Level 1 1st year students: Engineering, Materials Science, Design 67 materials, 77 processes

The CES EduPack 09

Level 2 2nd - 4th year students of Engineering and Materials Science and Design. 98 materials, 109 processes

Level 3 4th year, masters and research students. 2916 materials, 233 processes

The Periodic Table

© MFA 2009

Browse Select Toolbar Print Search web CES Help Search

Ceramics and glasses

Hybrids: composites etc

Metals and alloys

Polymers and elastomers

MaterialUniverse

+

+

+

+

Finding information with CES

File Edit View Select Tools Window Help Feature request

Class

Elastomers

Thermoplastics

Thermosets

Member

ABS

Polyamides

Polycarbonate

Polyethylene

PET

Polypropylene

PMMA

PTFE

MaterialUniverseMaterialUniverse

Edu Level 1Edu Level 1

Table:

Subset:

Find what

Look in table

Search

Materials

TitaniumPlexiglas

Polymethyl methacrylate (Acrylic, PMMA) The material When you think of PMMA, think transparency. Acrylic, or PMMA, is the thermoplastic that most closely resembles glass in transparency and resistance to weathering. The material has a long history: discovered in 1872, first commercialized in 1933, its first major application was as cockpit canopies for fighter aircraft during the second World War. Composition (CH3-CH2-C-CO-OCH3)n Image _ General properties Density 1.2e3 kg/m^3 Price 2.5 - 2.7 USD/kg Mechanical properties Young's modulus 2.2 - 3.8 GPa Yield strength (elastic limit) 54 - 72 MPa Tensile strength 48 - 80 MPa Compressive strength 72 - 1.3e2 MPa Elongation 2 - 10 % Hardness - Vickers 16 - 22 HV Fatigue strength at 10^7 cycles * 15 - 33 MPa Fracture toughness 0.7 - 1.6 MPa.m^1/2 Thermal properties Glass temperature 3.6e2 - 4.4e2 K Maximum service temperature 3.2e2 - 3.3e2 K etc

Acrylonitrile butadiene styrene (ABS) The material ABS (Acrylonitrile-but can now be transparent, and it can be given vivid colors. ABS-PVC alloys are tougher than standard adiene-styrene) is tough, resilient, and easily molded. It is usually opaque, although some grades ABS and, in self-extinguishing grades, are used for the casings of power tools. Composition : (CH2-CH-C6H4)n General properties Density 1010 - 1210 kg/m^3 Price 2.33 - 2.56 USD/kg Mechanical properties Young's modulus 1.1 - 2.9 GPa Yield strength (elastic limit) 18.5 - 51 MPa Tensile strength 27.6 - 55.2 MPa Elongation 1.5 - 100 % Hardness - Vickers 5.6 - 15.3 HV Fatigue strength at 10^7 cycles 11.04 - 22.08 MPa Fracture toughness 1.186 - 4.289 MPa.m^1/2 Thermal properties Maximum service temperature 335 - 350 K Thermal conductor or insulator? Good insulator Thermal conductivity 0.188 - 0.335 W/m.K Specific heat capacity 1386 - 1919 J/kg.K Thermal expansion coefficient 84.6 - 234 µstrain/°C Etc …..

© MFA 2009

Adding the science

General propertiesDensity 2500 - 2900 kg/m^3Price 2.3 - 2.86 USD/kg

Mechanical propertiesYoung's modulus 68 - 80 GPaYield strength (elastic limit) 95 - 610 MPaTensile strength 180 - 620 MPaElongation 1 - 20 %Fatigue strength at 10^7 cycles 57 - 210 MPaFracture toughness 21 - 35 MPa.m^1/2

Thermal propertiesMelting point 495 - 640 °CMaximum service temperature 120 - 200 °CThermal conductivity 118 - 174 W/m.KThermal expansion coefficient 22 - 24 µstrain/°C

Electrical propertiesElectrical resistivity 3.8 - 6 µohm.cm

Description. The high-strength aluminum alloys rely on age-hardening: a sequence of heat treatment steps that causes the precipitation of a nano-scale dispersion of intermetallics that impede dislocation motion and impart strength.

Age-hardening wrought Al-alloys

Definitions and measurement. Figure 1 shows a typical tensile stress-strain curve. The initial part is linear (Hooke’s law), and it is elastic, meaning that the strain is recoverable – the material returns to its original shape when the stress is removed. Stresses above the elastic limit cause permanent deformation or fracture ………

The origins of moduli. Atoms bond together, some weakly, some strongly. If they bind strongly enough they form solids; the stronger the bond, the higher is the melting point of the solid. Think of the bonds as little springs (Figure 3). The atoms have an equilibrium spacing ; a force pulls them apart a little, to , but when it is released they jump back to their original spacing. . ……….

Young’s modulus

Measurement of Young’s modulus

Origins of the modulus

Definitions and measurement. Material subjected to repeated stress cycles may fail even when the peak stress is well below the tensile strength, or even below that for yield. Fatigue data are measured and presented as curves, where is the range over which the stress varies and Nf

is the number of cycles to failure………

How do fatigue cracks propagate? Holes, change of section, cracks, and surface scratches concentrate stress so that, even when the sample as a whole remains elastic (the “high-cycle” regime), local plasticity occurs. The damage this creates accumulates, finally developing into a tiny crack. The crack propagates in the way shown on the left of Figure 2. ……….

Fatigue strength at 107 cycles

Author Title Chapter

Callister “Materials Science and Engineering: an Introduction” 6

Budinski “Engineering Materials: Properties and Selection” 2

Askeland “The Science and Engineering of Materials” 6

Ashby et al “Materials: Engineering, Science, Processing and Design” 6, 7

Ashby & Jones “Engineering Materials” Vol 1 8, 9

© MFA 2009

Select Toolbar Print Search web Browse Search

Changing the units, customize the system

File Edit View Select Tools Window Help Feature request

Eco audit

Supporting info

License key

Options

Sheet Number Graph Labels Units

Preferred Currency

Preferred Unit system

Absolute units for temperature

Display units for temperature

US dollar

Metric

© MFA 2009

Help! White papers, indices, more

CES Help Select Print Search web Search Browse White Papers

'Teaching Engineering Materials', M.F. Ashby, D. Cebon (PDF, 5.5 MB) Download

'Teaching Materials and Processes to First and Second Year Students', M.F. Ashby (PDF, 400 KB)

Download

'Materials and Product Design', M.F. Ashby (PDF, 800 KB) Download

'The CES EduPack Database of Natural and Man-Made Materials', M.F. Ashby (PDF, 1.7 MB)

Download

'The CES Database for Architecture and the Built Environment - background reading', M.F. Ashby, J. Fernandez, and A. Gray (PDF, 680 KB)

Download

'The CES Eco-selector - background reading', M.F. Ashby, A. Miller, F. Rutter, C. Seymour, and U.G.K. Wegst (PDF, 1.5 MB)

Download

'The CES Eco Audit tool – a white paper', M.F. Ashby, N. Ball, and C. Bream (PDF) Download

© MFA 2009

Unit 1: The main points

• The data take two broad forms:

(a) numeric, non-numeric data that can be structured in a uniform way for all materials

(b) documentation, usually in the form of text and images

• Classification allows materials data to be organized and retrieved

• CES allows rapid access to information by

Browsing

Searching

Exploring the science

© MFA 2009

Pause for demo

© MFA 2009

Exercises: Browsing

1.1 Find, by browsing, the Level 1 record for Titanium alloys in Metals and alloys: Non-ferrous

1.2 Find the Level 1 record for Phenolics in Polymers and elastomers: Thermosets

1.3 Find the Level 1 record for Alumina in Ceramics and and elastomers: Technical ceramics

1.4 Find the Level 2 record for Age-hardening wrought aluminum alloys in in Metals and alloys: Non-ferrous: Aluminum alloys

1.5 Find the Level 2 record for Plywood in in Hybrids: Natural materials

Browse Select Search

File Edit View Select Tools Window



Metals and alloys


MaterialUniverse

+

+

+

+


Edu Level 1Edu Level 1Subset:

Table:





Metals and alloys


MaterialUniverse

++

++

++

++


Edu Level 1Edu Level 1Subset:

Table:

© MFA 2009

Exercises: Searching

1.6 Find, by searching, the record for Polylactide: what is it?

Answer: Polylactide, PLA, is a biodegradable thermoplastic derived from corn.

1.7 Find records for materials that are used for Lenses: what are they?

Answer: Silicon, Polyamides (PA), Polycarbonate (PC) and Acrylic (PMMA).

1.8 Find records for any material that is a Biopolymer.

Answer: Natural rubber (NR);

Cellulose polymers (CA);

Polylactide (PLA);

Poly_something_unpronounceable (PHA, PBA);

Starch-based thermoplastics (TPS)

Find what:

Look in table: MaterialUniverse


Polylactide


© MFA 2009

Exercises: Exploring the science

M e c h a n ic a l p r o p e r t i e sY o u n g ’ s m o d u l u s

F r a c t u r e t o u g h n e s s

… … . .

T h e r m a l p r o p e r t i e sT h e r m a l c o n d u c t i v i t y

M a x i m u m u s e t e m p e r a t u r e

… … . .

E le c t r i c a l p r o p e r t i e sE l e c t r i c a l c o n d u c t i v i t y

D i e l e c t r i c s t r e n g t h

… … . .

E c o p r o p e r t i e sE m b o d i e d e n e r g y

C O 2 f o o t p r i n t

… … . .

Y o u n g ’ s m o d u l u s

D e f i n i t i o n … … … … … … … … … … … …… … … … … … … … … … … … … … … … …… … … … … … … .… … … … … … … .

M e a s u r e m e n t… … … … … … …… … … … … … … .… … … … … … … .

O r i g i n s… … … … … … …… … … … … … … .… … … … … … … .

M e c h a n ic a l p r o p e r t i e sY o u n g ’ s m o d u l u s

F r a c t u r e t o u g h n e s s

… … . .

T h e r m a l p r o p e r t i e sT h e r m a l c o n d u c t i v i t y

M a x i m u m u s e t e m p e r a t u r e

… … . .

E le c t r i c a l p r o p e r t i e sE l e c t r i c a l c o n d u c t i v i t y

D i e l e c t r i c s t r e n g t h

… … . .

E c o p r o p e r t i e sE m b o d i e d e n e r g y

C O 2 f o o t p r i n t

… … . .


D e f i n i t i o n … … … … … … … … … … … …… … … … … … … … … … … … … … … … …… … … … … … … .… … … … … … … .

M e a s u r e m e n t… … … … … … …… … … … … … … .… … … … … … … .

O r i g i n s… … … … … … …… … … … … … … .… … … … … … … .


D e f i n i t i o n … … … … … … … … … … … …… … … … … … … … … … … … … … … … …… … … … … … … .… … … … … … … .

M e a s u r e m e n t… … … … … … …… … … … … … … .… … … … … … … .

O r i g i n s… … … … … … …… … … … … … … .… … … … … … … .

1.11 What is meant by the CO2 footprint of a material?

Answer: The CO2 footprint per unit weight, using PET as an example, is

yearpershippedPETofMass

yearperproductionPETfromgsinaridirectlyCOofMassCO 2

PET2

1.9 How is Fracture toughness measured?

Figure 1. Measuring fracture toughness,1C.

Answer: Definition and measurement. The fracture toughness, , (units: MPa m1/2 or MN/m1/2) measures the resistance of a material to the propagation of a crack. It is measured by loading a sample containing a deliberately-introduced contained crack of length or a surface crack of length (Figure 1 ), recording the tensile stress or the bending load at which the crack suddenly propagates.

1.10 What does Dielectric breakdown mean?

Answer: Definition and measurement. The breakdown potential gradient or dielectric strength (units: MV/m) is the electrical potential gradient at which an insulator breaks down and a damaging surge of current like a lightning strike flows through it.

Figure 2. Breakdown involves a cascade of electrons like a lightening strike.

© MFA 2009

End of Unit 1

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UNIT 1-LN the Materials and Process Universe

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