Materials & Manufacturing

DEPT OF COMPUTING, ENGINEERING AND TECHNOLOGY
MODULE TITLE: Materials & Manufacturing

TITLE OF ASSESSMENT: Materials and Manufacturing Process Software Use
MODERATED: KR

PLEASE READ ALL INSTRUCTIONS AND INFORMATION CAREFULLY.

This is the second part of your Coursework Assignment 1. Assignment 1 contributes 50% to your final module mark, split equally between

parts A (25%) and B (25%).

Please ensure that you retain a duplicate of your assignment. We are required to send samples of student work to the external examiners

for moderation purposes. It will also safeguard in the unlikely event of your work going astray.

THE FOLLOWING LEARNING OUTCOMES WILL BE ASSESSED BY ASSIGNMENT 1: Knowledge
an understanding of:

1. The shaping methods used in modern manufacturing.
2. The behaviour of the main classes of engineering materials and their processing -related properties.

Skills

and the ability to:

4. Select the most appropriate manufacturing process for a particular component.

IMPORTANT INFORMATION
You are required to submit your work within the bounds of the University Infringement of Assessment Regulations (see your Programme

Guide). Plagiarism, paraphrasing and downloading large amounts of information from external sources, will not be tolerated and will

be dealt with severely. Although you should make full use of any source material, which would normally be an occasional sentence and/or

paragraph (referenced) followed by your own critical analysis/evaluation. You will receive no marks for work that is not your own. Your

work may be subject to checks for originality which can include use of an electronic plagiarism detection service.
Where you are asked to submit an individual piece of work, the work must be entirely your
own. The safety of your assessments is your responsibility. You must not permit another student access to your work. Where referencing

is required, unless otherwise stated, the Harvard referencing system must be used (see your Programme Guide).
EAT104: Coursework 1B: 2015/2016Session

Cambridge Engineering Selector (CES) Software

CES SOFTWARE

CES software is a tool designed to aid in the process of materials and manufacturing process selection. You will be given clear

instructions on how to use the software prior to attempting this exercise. CES has two main functions. It can be used as:

(i) a database of materials and processes

The software contains a great deal of very useful information about materials and manufacturing processes. For instance, you might

need to know about the mechanical and thermal properties of low density polyethylene. Alternatively you may want to find out

about the engineering applications of silicon nitride, or investigate the fundamentals of the hot isostatic pressing process.

Other questions which may be asked include:

• Which metal has the highest electrical conductivity?
• At what temperature does lead melt?
• What is the dielectric constant for borosilicate glass?
• How does the polymer extrusion process differ from injection moulding?
• What rapid prototyping methods are available and what are they used for?
• Who can supply aluminium sheet?
• What other aluminium section shapes are available?…. plus millions of
others……

(ii) a selection tool for materials and/or processes

CES is a powerful tool in helping to choose the most appropriate materials and manufacturing processes for engineering components.

In choosing a material for a given component, what sort of questions do we need to ask to make sure we get the correct choice? Such

factors include cost, performance (e.g. mechanical, thermal), size, shape etc. CES uses a particularly strong but simple

methodology to aid the materials selection process.

In terms of materials selection, how do you go about choosing the best material for a given engineering application? What material(s)

would be best suited for the manufacture of (say) bicycle forks, flywheels or pressure vessels? Knowing the right questions to ask

makes the process easier.

In terms of process selection, how do you go about choosing the best manufacturing process for a given component? For instance, how

would you select a process to manufacture large steel pressure vessels? How would you manufacture a polyethylene milk carton? To

answer such questions you need to know what distinguishes one manufacturing process from another. What questions must be asked to

decide which manufacturing process is best?
The methodologies employed within CES to aid selection of either materials or processes are quite similar. Each relies on knowing

which are the critical questions to ask.

THE CES EXERCISE

Your overall task is to become familiar with the use of the CES selection software. This piece of coursework involves a number of

different stages, each of which is described below, together with the submission requirements for each.

Note that for the purposes of this study, you should use “Edu Level 2″ database (this selection is done as soon as the software boots

up). The difference between Level 1, 2 and 3 databases is simply in the number of materials/processes in the database and the amount

of information held on each. For this task, the L3 database contains too many materials and this makes charts far too “busy” to be

clear. Hence we will employ the L2 database for clarity.

1. Navigating the databases

1.1 Materials Database

The purpose of this part of the exercise is to find out about the properties of the common classes of materials and compare & contrast

these properties. Your task is to find out about the mechanical, thermal and electrical properties of the following materials:

1. Polypropylene: [A Polymer]
2. Bamboo: [A wood]
3. Cast Aluminium Alloys: [A Metal]
4. Carbon Fibre Reinforced Plastic (CFRP): [A Composite]
5. Silicon Carbide; [A Technical Ceramic]

Draw up a table (as shown below) to compare properties. Discuss the property comparison. In particular, relate properties to

engineering applications. Where CES gives a range for a given property value (e.g. Young’s Modulus), then specify the midpoint of that

range. In particular, specify the significance of specific strength (tensile strength / density) and specific stiffness (Young’s

Modulus / density) to materials engineers. It is expected that you will conduct literature research outside of CES to complete this

section correctly. One side of A4 text (c 300-500 words) should suffice for this discussion.

Property
Material Young’s Modulus (E)
(GPa) Tensile Strength (u) (MPa) Density, ()
(g.cm-3) Specific
Stiffness
(E/) Specific Strength (u/) Electrical Conduction (Yes/No) Thermal Conduction (Yes/No) Max Service Temp
(C)

Polypropylene

Wood, typical (L)

Aluminium Alloy

CFRP

Silicon Carbide

1.2 Process Database

The purpose of this part of the exercise is to find out more about the characteristics of the common manufacturing processes used

to process metals, ceramics, polymers and composites.

The task is to select a process from each of the following categories and present a summary of each. For each process give an example

(or examples) of materials processed by the given technique.

1. Casting
2. Joining (via a thermal welding technique).
3. Extrusion
4. Composite lay-up techniques.
5. Injection Moulding
6. Powder Processing (sintering)
7. Laser-based Rapid Prototyping
8. Nitriding (a surface treatment)
2. Materials and Process Selection Charts

The use of CES as a material and process selection tool will be considered in much more detail in later years. However, you should

familiarise yourselves with selection charts and the method(s) by which they are generated.

2.1 Materials Selection Charts

A materials selection chart is a chart in which one material property is plotted against another. One such example is a plot of

stiffness (E: Young’s modulus) against density (). This chart can be used when selecting light stiff materials. This chart is shown

below:

Any given material will occupy a point on this chart. Families of similar materials will occupy larger areas (islands, ellipses,

bubbles etc) on the chart. The chart is effectively a map of materials in which their location is determined by their properties.

Similar charts can be drawn up for any combination of properties.
2.2 Process Selection Charts

Just as materials have properties or attributes, so do manufacturing processes. The
“properties” or attributes of a manufacturing process may include:

• Primary or secondary? Continuous or discrete?
• Surface finish achievable
• Dimensional tolerance or reproducibility
• Size (mass or volume) of components produced
• Economic batch size

A process selection chart plots one such attribute against another. The attribute may be quantitative (e.g. surface finish or component

mass) or qualitative (e.g. primary or continuous). In either event, a selection chart may be produced. A process selection chart in

which component mass is plotted for primary processes is shown below:

10000
1000

Fine Machining (Manual)

Filament Winding
Injection Blow Moulding

Injection Moulding (Thermoplastics)
100

3D Printing
10

1

0.1

0.01

Stereolithography
1e-3

Reaction Injection Moulding

1e-4

1e-5

1e-6

1e-7

1e-8

Fal se

T rue
Primary
Note that a process may be primary or not primary. These are the only options
(hence true v false).

2.3 Your Selection Chart Task

Plot and label the following selection charts (1, 2 and 3 are materials selection charts, 4 is a process selection chart):
1. Young’s Modulus (y-axis) v Density (x-axis). Insert a line of gradient = 1 and move it higher until you isolate a shortlist of

5-10 materials. Label and list these materials.

2. Elastic limit (or Yield Strength) (y-axis) v Density (x-axis). Insert a line of gradient
= 1 and move it higher until you isolate a shortlist of 5-10 materials. Label and list these materials.
3. Young’s Modulus/Density (E/: y-axis) v Elastic Limit /Density (y/: x-axis).
Place a box in the right hand corner of this chart to isolate 10-15 materials with
high values of BOTH E/ and y/ ratios. Label and list these materials in your box. How do your results compare to the results from

charts 1 and 2 above?

4. Mass range (y-axis) v Material class (Materials/Polymer/Thermoplastic) (x-axis).
For this final (process) selection chart (i.e. Chart 3) add a box which covers the mass range 100g to 400g. Label representative

processes.
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