Unit 5: Introduction to Engineering Materials · PDF fileUnit 5: Introduction to Engineering Materials AS: ... Unit 7: Engineering the Future ... engineering materials AS 10

© Pearson Education Ltd 2008 Engineering page 1 of 3 Level 1 Foundation Diploma Unit 5

Unit 5: Introduction to Engineering Materials

AS: activity sheets

TOPIC The properties that are used to describe the performance of engineering materials

LEARNING OUTCOME LO1 Know about the properties that are used to describe the performance of engineering materials

Topic information Delivery methods Guidance Resources

This topic investigates why it is important for design engineers to know about the properties of materials when deciding on which type of material to use for a particular product.

Mechanical properties of materials:

strength, hardness, toughness, brittleness, malleability, ductility

Other (non-mechanical) properties of materials:

electrical and thermal conductivity, corrosion and solvent resistance, environmental degradation resistance

Properties which affect the performance of a product when in service.

Teacher presentation introducing the three learning outcomes, which are interrelated.

Before embarking on individual research, a good way to introduce the topic would be to play a ‘matching cards’ game, as it will stimulate debate. Use two sets of cards:

1. a range of properties

2. features of the properties

Link a property to its feature, e.g. hardness + resistance to indentation.

Teacher-led discussion, using case studies, followed by small group or pair work.

The bulk of the work for the whole unit should be delivered using learner-centred practical activities, reinforced with integrated theory.

The assignment can be introduced at any point during delivery, but it will work better if tasks are timed to coincide with completion of the relevant activity sheets.

Explain that when a designer chooses a material for a product their decision is influenced by the performance requirements of the product, and the manufacturing methods available to them.

Explain that the mechanical properties of materials are those that involve force when they are being evaluated, e.g. pressing, pulling, abrading, scratching, twisting, hitting, etc.

Look at a range of products, identifying material properties that are important for each, e.g. corrosion- (water) and solvent- (dishwasher powder) resistant cutlery.

AS 1 Mechanical properties 1.1 Defining properties 1.2 Stress in components AS 2 Non-mechanical properties of materials AS 3

Properties of materials that have a significant effect on the performance of a product when in service


TOPIC The materials that engineers use and material forming processes

LEARNING OUTCOME LO2 Know about the materials that engineers use and their forming processes


This topic introduces learners to some of the more commonly used materials that are formed into engineered products. Ferrous and non-ferrous metals that engineers use: cast iron, plain carbon steels, stainless steel, high speed steel, copper, tin, zinc, lead, aluminium, brass, bronze, solder, aluminium alloy Thermoplastic and thermosetting polymeric (plastic) materials that engineers use: PVC, nylon, PTFE, perspex, polythene, rubber, Bakelite, Formica, melamine, fibre reinforced (Kevlar, glass and carbon fibre) Processes: cutting and forming raw materials into components

Before embarking on individual research, a good way to introduce the topic would be to play a ‘matching cards’ game, as it will stimulate debate. Use three sets of cards: a range of properties materials products Link a property to a material and a product, e.g. corrosion resistance + stainless steel + saucepan. Teacher-led discussion surrounding looking at samples of engineering materials that have been labelled. Pair work to investigate forming processes, including looking at the animations of processes found by using the web links given in the Resource List for this unit.

The link between service requirements, properties and manufacturing processes should be discussed. A good starting point might be to ask why the bodies of domestic cars are not made of stainless steel, given its property of non-corrodibility. Equal emphasis should be given to metallic and non-metallic materials. A set of sample materials can be obtained from the Institute of Materials, Minerals and Mining by joining the schools affiliate scheme: http://www.iom3.org/education/sas.htm This activity can be linked to Unit 2: Practical and Engineering Skills – LO 2 and activity sheet 3 (Cutting materials) and activity sheet 4 (Forming materials).

AS 4 Ferrous and non-ferrous metals that engineers use AS 5 Polymeric (plastic) materials that engineers use AS 6 Forming processes that are used to turn raw materials into products


TOPIC Identifying and testing materials

LEARNING OUTCOME LO3 Be able to identify engineering materials and carry out tests to evaluate their properties


This topic investigates how designers communicate information about material requirements on drawings and in documentation. Specifying materials on documentation, using recognised conventions This is then followed by practical activities, which involve identifying and testing materials. Identifying engineering materials by carrying out visual and tactile inspection Testing to evaluate the mechanical properties of engineering materials – tensile strength, impact strength, hardness Finding out about the engineering company where work experience will be done.

Teacher-led discussion followed by pair work, where learners identify materials specified on drawings and documentation. A ‘matching cards’ game could be used to stimulate debate. Use four sets of cards:

1. material 2. surface colours 3. mass (e.g. lightweight) 4. surface texture

Link a material to a colour, mass and texture, e.g. stainless steel + silvery + heavy + smooth. Pair work to investigate specimens of materials or components from a dismantled product. Demonstration of how to change the properties of a material by heating and quenching. Practical activities could include carrying out basic tests on metals and polymers, e.g. scratch, impact by hammering, tension. Further details can be found in the Delivery Guidance in the Unit Specification. Individual research by the learner, supported by discussion with the teacher.

Learners should be shown exemplars of engineering drawings and related manufacturing documentation. Explain why shorthand notation (e.g. BDMS) is used, and why there is the need for recognised conventions. Refer back to the labelled material samples used in LO 2. This activity can be linked to Unit 2: Practical Engineering and Communication skills – LO 3 and activity sheet 7 (Dismantling and assembling an engineered product), and to Unit 7: Engineering the Future – LO 2 and activity sheet 5.1 (Recycling a domestic appliance). Learners should calculate the stress in a piece of material when it breaks, or be able to convert a hardness reading into a hardness value using a conversion table, e.g. finding the Vickers Pyramid Number. Remind learners that they should find out about specifying and testing materials when they are on work experience.

Activity sheet 10 can be undertaken at any appropriate point during delivery of the unit. The learner should be given the name and contact details of the person who will be responsible for them when at work.

AS 7 Specifying materials on documentation AS 8 Identifying engineering materials by carrying out visual and tactile inspection AS 9 Testing to evaluate the mechanical properties of engineering materials AS 10

Preparing for work experience


Unit 5: Mechanical properties of materials

Activity Sheet 1

1.1 Defining properties The mechanical properties of materials are used to describe the way that engineering materials behave when they are subjected to loading and shaping. Using the following link as a starting point, work with another learner to complete the table below: http://www.bbc.co.uk/schools/gcsebitesize/design/resistantmaterials/materialsmaterialsrev3.shtml

Property Definition

Tensile strength The stress at which a material fails when subjected to a tensile load (a pulling force).

Compressive strength

Hardness

Toughness

Brittleness

Malleability

Ductility

1.2 Stress in components Find a definition for stress. What are the units of stress?

Investigate why engineering designers calculate the values of stresses in components. Write up your findings as a short report, which should include a diagram.

Think about some of the products that you use, e.g. a bicycle, sports equipment, games console. Have any of them ever failed mechanically, i.e. has a part broken off? If so, what caused this to happen?


SKILLS PROFILE Activity 1 provides opportunities to develop the following skills:

Skill

Practical Use of computer

Personal, learning and thinking (PLTS) ASK: Independent enquirer[analyse and evaluate information, judging its relevance

Functional

ICT Find and select information Develop, present and communicate information


Unit 5: Non-mechanical properties of materials

Activity Sheet 2

2.1 Defining properties Properties of materials are used to describe the way that engineering materials behave in service. Using the following link as a starting point, work with another learner to complete the table below: http://www.bbc.co.uk/schools/gcsebitesize/design/resistantmaterials/materialsmaterialsrev3.shtml

Property Definition

Thermal conductivity

Electrical conductivity

Corrosion resistance

Solvent resistance

Resistance to environmental degradation


Skill

Practical n/a


Functional

ICT Find and select information Develop, present and communicate information


Unit 5: Properties of materials that have a significant effect on the performance of a product when in service

Activity sheet 3

3.1 Complete the following table:

Property A product for which the property is very important –and the reason why

Tensile strength The tow bar fitted to a heavy recovery vehicle – if it fails, a lorry which it is pulling will break away and crash.

Compressive strength

Hardness

Toughness

Brittleness

Malleability

Ductility

Thermal conductivity The base of a saucepan – so that when it is on a heat source the heat can get through quickly and cook the food.

Electrical conductivity

Corrosion resistance

Solvent resistance

Resistance to environmental degradation


Use this link to find information about the different types of incandescent light bulbs available in the shops: http://www.bltdirect.com/products.php?cat=66

Inside the bulb is a metal filament, which glows when an electric current is passed through it.

• What type of metal is used for the filament? • Describe three properties that the material must have if it is to perform properly.


Skill

Practical n/a


Functional

n/a


Unit 5: Ferrous and non-ferrous metals that engineers use

Activity sheet 4

If a metal is said to be ferrous, what does this mean?

Many components in cars are made from aluminium alloy. What is an alloy?

Copper is a very good conductor of electricity and is used for the inner core of electrical wiring in houses. Investigate why the pins of a 13 amp plug are made from brass, given that brass is not as good a conductor as copper.

Complete the following table:

Material Ferrous/ Non-ferrous

A component made from the material Reason for choosing the material

Cast iron

Plain carbon steel

Stainless steel

High speed steel

Aluminium

Aluminium alloy

Brass

Bronze

Tin

Zinc

Solder

Lead


Use this link to try a quiz about metals and products: http://www.design-technology.org/metalspresentation.ppt


Skill

Practical n/a


Functional

n/a

Unit 5: Polymeric (plastic) materials that engineers use


Activity sheet 5

Polymeric materials are classified as thermoplastics (T), thermosetting plastics (TS) and elastomers. Complete the following table:

Material T or TS A component made from the material Reason for choosing the material

LDPE

HDPE

Nylon

PVC

Perspex

PTFE

Natural rubber

Neoprene

Silicone rubber

Bakelite

Formica

Melamine

Kevlar

Glass


Fibre reinforced epoxy resin

Fibre reinforced polyester resin

Write down the full names for the abbreviations LDPE, HDPE, PVC and PTFE.

Which of the products in the table can be fully recycled when they are not wanted anymore?

Thermosetting plastics are also called ………………………………………………?


Skill

Practical n/a


Functional

n/a


Unit 5: Forming processes that are used to turn raw materials into products

Activity sheet 6

6.1 Complete the following table:

Process A material that can be formed by the process A product made by the process

Die casting

Forging

Drawing

Rolling

Pressing

Machining

Injection moulding

Vacuum forming

Metal extrusion

Plastic extrusion

Laying up

Vulcanising


6.2 Kenwood manufacture food processing equipment for use in homes and restaurants.

Use this link to find information about their food mixers:

http://www.kenwoodworld.com/uk/catering_product_detail.php?cat=304&id=54 Look at the image of the XKM810 food mixer and notice that it has a plastic bowl. Now select ‘catering product categories’ and look at the food mixer which has a metal bowl.

Why have different materials been chosen for the bowls?

How do you think the bowls are formed?

For each material, name one property that allows it to be easily formed into the shape of a bowl.

Discuss your findings with your teacher or another learner.

6.3 Use the link below to find an image of a bicycle, which you should copy and paste into a word document. Print it off and, by hand, identify and number six components. Now complete the table.

http://www.bicyclemagic.com/index.html

Component The process used to form it to shape

The material the component is made from

A property that the material must have

1

2

3

4

5

6



Skill

Practical n/a


Functional

English Speaking and listening – take full part in formal and informal discussions/exchanges


Unit 5: Specifying materials on documentation

Activity sheet 7

When reading engineering drawings and other types of documentation, it is very important to know what the abbreviations used mean. For example, what would MS mean in the title block of a drawing? (Answer: mild steel)

Title: Mounting bracket Dwg. No.: 006 Drawn: ABC Checked: XYZ Scale: 1:1 Projection: 3rd Angle Material: MS

7.1 Draw a straight line to connect the abbreviation to its correct meaning:

Abbreviation Material

CI Polypropylene

BDMS Carbon fibre reinforced polymer

PTFE Duralumin

CFRP Cast iron

Dural Stainless steel

GFRP High speed steel

HSS Bright drawn mild steel

PP Polyvinyl chloride

PVC Glass fibre reinforced polymer

SS

Polytetrafluoroethylene

To manufacture a product in a workshop you need a drawing, tools and raw materials. The materials will be collected from a storage area and you need to know what sizes to ask for. This information is very often given on the drawing: Material: SWG 10 MS sheet The material is: Standard wire gauge 10 (3.25 mm thick) mild steel sheet.


7.2 Work with another learner to investigate other abbreviations (ask your teacher for some engineering drawings that you can look at) and complete the following table:

Abbreviation What you should ask for when collecting raw materials from the stores

Dural Ф20 × 1 × 300 mm tube

BDMS Ф12 × 100 mm

SS 10 × 5 × 100 mm rect.

UPVC 150 × 25 × 15 × 2000 mm L-shaped section

HDPE outer DIA 20 mm, inner DIA 15 mm × 3 m


Skill

Practical n/a


Functional

Mathematics Identify and obtain necessary information to tackle the problem


Unit 5: Identifying engineering materials by carrying out visual and tactile inspection

Activity sheet 8

This activity involves looking at a selection of materials and trying to identify what they look or feel like. Visual inspection can be done by eye, using a simple magnifier or with a microscope. Tactile inspection involves running your fingers over the material, pressing and holding it, so that you can get a ‘feel’ for what it is. Some materials have a distinctive smell and this can help with the identification process. 8.1 Draw a straight line to link the colour to the correct material:

Material Surface colour and appearance

Grey cast iron Silver, shiny, smooth

Copper White, shiny, very smooth

Formica Dull white, smooth

BDMS Grey granular

UPVC Yellow, smooth

Galvanised steel Brown, woodgrain effect

Brass Yellow, fibrous

Kevlar Red, smooth

Nylon

Grey, feathery

8.2 Work with another learner to either dismantle a domestic appliance, which your teacher will give you, or obtain a selection of pre-prepared material samples.

Select about six components or samples and try to identify what the materials are.



Skill

Practical n/a


Functional

Mathematics Select and apply skills in an organised way to find solutions to practical problems for different purposes


Unit 5: Testing to evaluate the mechanical properties of engineering materials

Activity sheet 9

Evaluating the properties of a material involves measurement and calculation. For example, if you carry out a tensile test on a piece of mild steel, you would expect the tensile strength to be about 240 MPa. However, there are much simpler tests that involve no numbers but which show how properties can be significantly altered.

9.1 Under the guidance of your teacher, try this test:

Find a short length of a single strand piano or guitar string.

Put on some eye protection.

Grip one end in a vice and try to snap the string in two, using pliers – you can’t do it!

Remove the string from the vice, hold one end with the pliers and use a gas flame to heat up a small part of the string to red heat.

Quench rapidly in water.

Now try to snap it at the point where it was heated. What happens now? At the point where it was heated, the string’s properties have changed. The material has become less ……………................and much more …………..………………. Investigate why heating and quenching made this happen. In the first activity sheet, you found a definition for engineering stress and you should also have discovered that to calculate the stress in a piece of material you divide the load it is carrying by its cross-sectional area, that is, Stress = (load in Newtons) ÷ (cross-sectional area in m2)

This table gives the results of a tensile test on two pieces of metal bar:

Metal Bar diameter (mm) Load to break it (kN) Tensile strength (MPa)

Copper 5 4.12

Brass 3 2.26

9.2 Calculate the tensile strengths, compare the figures and say which material is stronger.


9.3 The two materials are now hardness tested by pressing with a pointed diamond. Here are the results:

Metal VPN

Copper 60

Brass 125

Investigate what VPN stands for.

Which material is harder?

Compare the hardness property for the two materials.


Skill

Practical Working with equipment

Personal, learning and thinking (PLTS)

ASK: Independent enquirer [explore issues, events or problems from different perspectives] MANAGE: Self-manager [work towards goals, showing initiative, commitment and perseverance]relevance and value]

Functional

Mathematics Identify and obtain necessary information to tackle the problem


Unit 5: Preparing for work experience

Activity sheet 10

Before starting work experience you should find out about the business where you are to be placed. This is so that on your first day you will know what to expect and be able to talk to people in a knowledgeable and interested way. Company employees will be giving up their time to look after you, and you will create a good impression if you are well informed. Complete the following checklist by gathering information from the company website, emailing or writing to a named contact at the company, or by using other sources of data.

Full company name

Address

Is it a UK, a European or a global business?

For how many years has the business been established?

What products are manufactured at the site where you will be placed?

What types of customer does the business sell to?

What was the value of company sales last year?

Does the company have competitors making the same type of product(s)?

How many people work on site?

What is the name of the person with overall responsibility for the site?

What types of materials does the factory process?


Who is responsible for ordering raw materials?

Who will be meeting you on your first day, and how do you keep in contact with them?

What do you need to bring with you on your first day?


Unit 5: Introduction to Engineering Materials General guidance:

The purpose of this assignment is to provide a framework within which the requirements of all the assessment foci for the unit can be achieved.

The assignment is broken down into three tasks, with activities based on those suggested in the ‘Approaches to Assessment’ section of the Unit Specification.

The assignment should take about 6 hours to complete.

Learner evidence should be presented in the form of a portfolio, which includes witness statements/observation records and annotated photographs confirming competence, where practical activities have been undertaken.

When marking learner work, the teacher should refer to the section in the Unit Specification headed ‘Guidance for Allocating Marks’ (reproduced in full at the end of this document). Detailed information is given about what to look for in a learner’s work when awarding marks across the three grading bands.

On completion of the assignment, two marks are awarded: Mark A and Mark B.

– Mark A is awarded on the basis of the content of the portfolio submitted by the learner.

– Mark B is awarded on the basis of the teacher’s observation of how well the learner worked, along with any written responses for some of the activities.


Task 1 This covers three assessment foci and is a research and written activity. Assessment Focus Band 1 Band 2 Band 3

LO 1 Know about the properties that are used to describe the performance of engineering materials. (Mark A)

States four different material properties that describe the performance of engineering materials. (1–4)

States four different material properties that describe the performance of engineering materials and defines three of them. (5–7)

States four different material properties that describe the performance of engineering materials, defines three of them and explains how the application of two materials (each with a different material property) would be affected. (8–9)

Assessment Focus Band 1 Band 2 Band 3 LO 2.1 Know about ferrous metals and their forming processes. (Mark A)

Gives an appropriate forming process and an engineering application for each of three different ferrous metals. (1–3)

Gives an appropriate forming process and an engineering application for each of three different ferrous metals and describes the properties of two of them. (4–5)

Gives an appropriate forming process and an engineering application for each of three different ferrous metals, describes the properties and justifies the use of the forming process of two of them. (6–7)

Assessment Focus Band 1 Band 2 Band 3 LO 2.2 Know about non-ferrous metals and their forming processes. (Mark A)

Gives an appropriate forming process and an engineering application for each of three different non-ferrous metals. (1–3)

Gives an appropriate forming process and an engineering application for each of three different non-ferrous metals and describes the properties of two of them. (4–5)

Gives an appropriate forming process and an engineering application for each of three different non-ferrous metals, describes the properties and justifies the use of the forming process of two of them. (6–7)


Activities for Task 1

Focus LO 1

Part of your work experience is spent in the design department of a company which manufactures leisure products for the garden. The factory uses large quantities of metals, and the product line includes barbecues, patio heaters, metal furniture and gazebos. Manufacturing (forming) processes used by the company include pressing thin metal sheet, bending tubes, welding, casting and finish machining of small components, and casting and polymer coating of large components. The chief designer is always looking for ways to expand the product range and tells you that a crucial part of the design process is selecting the correct materials and forming processes for the components being manufactured. He explains about an earlier problem with a barbecue lid, which cracked when being pressed to shape – the raw materials supplier had sent the wrong type of steel plate. To prevent this happening again, all materials coming into the factory are tested so that their properties can be confirmed. A meeting has been arranged with the chief buyer for a UK chain of garden centres in order to discuss new product ideas. The company would like you to attend the meeting, but the chief designer needs to be sure that you are well informed about the properties of materials. They want to find out if you know how the properties of a material affect the way it performs in service and is formed into a product. You are asked to write a short report covering the following points:

a. State four different properties that relate to materials and briefly describe how they affect the performance of the material.

b. Choose three of the properties identified in (a) and write a definition for each of them.

c. Choose two of the properties from (a) and explain the effect of each on the performance of a material that has been used in the manufacture of a product, which is being used in service.

Focus LO.3

d. Choose three different ferrous metals and state an appropriate forming process and engineering application (use) for each of them.

e. Clearly describe the properties of two of the ferrous metals that you identified in (d).

f. Using examples of products, justify the use of the forming process for the two ferrous metals that you have chosen.

Focus LO 2.2

g. Choose three different non-ferrous metals and state an appropriate forming process and engineering application (use) for each of them.

h. Clearly describe the properties of two of the non-ferrous metals that you identified in (g).

i. Using examples of products, justify the use of the forming process for the two non-ferrous metals that you have chosen.


Learner guidance for Task 1 Before starting the activities, please read the introduction carefully and discuss it with your teacher. It is

important to establish the link between properties of a material, the way it behaves when formed into a product, and the manufacturing processes used to form it.

To achieve higher marks, you must provide clear descriptions for activities (e), (f), (h) and (i). Your descriptions should be a combination of written text, diagrams and images.


Task 2

This covers three assessment foci and is a research and written activity.

Assessment Focus Band 1 Band 2 Band 3

LO 2.3 Know about thermoplastics and elastomers and their forming processes. (Mark A)

Gives an appropriate forming process and an engineering application for each of two different thermoplastics and one elastomer material. (1–3)

Gives an appropriate forming process and an engineering application for each of two different thermoplastics and one elastomer material and describes the properties of one thermoplastic and one elastomer. (4–5)

Gives an appropriate forming process and an engineering application for each of two different thermoplastics and one elastomer material, describes the properties and justifies the use of the forming process of one thermoplastic and one elastomer. (6–7)


LO 2.4 Know about thermosetting plastics and their forming processes. (Mark A)

Gives an appropriate forming process and an engineering application for each of three different thermosetting plastic materials. (1–3)

Gives an appropriate forming process and an engineering application for each of three different thermosetting plastic materials and describes the properties of two of them. (4–5)

Gives an appropriate forming process and an engineering application for each of three different thermosetting plastic materials, describes the properties and justifies the use of the forming process of two of them. (6–7)


Focus LO 2.3

In task 1 you investigated the properties of metals. You are now going to investigate polymeric materials. You are doing your work experience in a factory that makes huge quantities of plastic components for the domestic car industry. The product range includes small trim fittings, instrument panels, door and boot seals, engine components, front and rear light clusters, bumpers and grilles. The company also has a specialist division, which produces custom-made fibre reinforced body panels for high-performance sports cars. The factory processes thermoplastics, thermosetting plastics and fibre reinforcing material. You are working with a manufacturing engineer who has arranged a meeting with a car company to discuss a new design. They would like you to attend the meeting, but need to be sure that you are well informed about the properties of polymers. They want to find out if you know how the properties of polymers affect the way they perform in service and how they are formed into a product. You are asked to write a short report covering the following points:

a. Choose two different thermoplastic materials and one elastomer and state an appropriate forming process and engineering application (use) for each of them.

b. Clearly describe the properties of one of the thermoplastic materials and the elastomer that you identified in (a).

c. Using examples of products, justify the use of the forming process for the two materials chosen in (b).

d. Choose three of the properties identified in (a) and write a definition for each of them.


e. Choose two of the properties from (a) and explain the effect of each on the performance of a material that has been used in the manufacture of a product, which is being used in service.

Focus LO 2.4

f. Choose three different thermosetting plastic materials and state an appropriate forming process and engineering application (use) for each of them.

g. Clearly describe the properties of two of the materials that you identified in (d).

h. Using examples of products, justify the use of the forming process for the two materials chosen in (e).

Learner guidance for Task 2 Before starting the activities, please read the introduction carefully and discuss it with your teacher. It is

important to establish the link between properties of a material, the way it behaves when formed into a product, and the manufacturing processes used to form it.

To achieve higher marks, you must provide clear descriptions for activities (b), (c), (e) and (f). Your descriptions should be a combination of written text, diagrams and images.


Task 3

This covers three assessment foci and is a mix of research, written and practical activities.


LO 3.1 Identify materials specified on an engineering drawing or service schedule. (Mark A)

Describes how three given different engineering materials are shown in abbreviated form on an engineering document. (1–3)

Describes how three given different engineering materials are shown in abbreviated form on an engineering document and identifies two other materials that are specified on a given engineering document. (4–5)

Describes how three given different engineering materials are shown in abbreviated form on an engineering document and identifies two other materials that are specified on a given engineering document, together with the forms of raw material and their dimensional requirements. (6–7)


LO 3.2 Identify engineering materials. (Mark B)

Identifies the materials from which three given engineering components are made by carrying out a visual and tactile inspection. (1–3)

Identifies the materials from which three given engineering components are made by carrying out a visual and tactile inspection and describes the properties of two of them. (4–5)

Identifies the materials from which three engineering components are made by carrying out a visual and tactile inspection, describes the properties of two of them and justifies their selection for the component. (6–7)


LO 3.3 Carry out tests on engineering materials. (Mark B)

Carries out two given tests on two given engineering materials to evaluate given mechanical properties. (1–4)

Carries out two given tests on two given engineering materials to evaluate and compare given mechanical properties. (5–6)

Selects and carries out two appropriate tests on two given engineering materials to evaluate and compare given mechanical properties. (7–9)



Focus LO 3.1

Every component has a drawing, which specifies dimensions and other information. a. Describe how the following three materials are shown in abbreviated form on engineering drawings

and documents: o bright drawn mild steel o aluminium alloy (Duralumin) o high-density polythene

b. Identify the materials in the following parts list:

Part No. Description Material Stock size

1 Pin SS Ф15

2 Facia panel UPVC 200 × 25 × 15 L-shape profile

As raw materials arrive, they are examined and tested for quality purposes, so that the company knows exactly what it is paying for. Describe the form of supply for the materials listed in the table, i.e. their shape and dimensions when delivered to a workshop as raw materials.

Focus LO 3.2

Your teacher will give you three engineering components.

c. Carefully examine the three engineering components that you have been given and identify the materials from which they are made, using visual and tactile inspection.

Now select two of the components. d. Describe the properties of the materials you have identified. e. Justify why the materials were selected for the components.

Focus LO 3.3

Your teacher will allow you access to some simple test equipment and give you two different engineering materials. f. Using the test equipment, carry out a tensile test and a surface hardness test on the materials. Use the data you have gathered to evaluate (rough calculations) the tensile strength and surface hardness of each material. Compare the mechanical properties that you established in activity (g) and present them in a short report.

Learner guidance for Task 3 For activity (d), your teacher will give you three components, each made from a single material, to

examine. Visual examination can be by eye, using a magnifier or by looking through a microscope. Tactile examination involves feeling the surface with your fingers, i.e. pressing, rubbing and scratching.

To obtain marks in band 3, you must choose the tests and equipment needed for activity (g). (There must be very little guidance from your teacher.)


Teacher guidance for all tasks The tasks provide learners with the opportunity to generate evidence that meets the requirements of the

three mark bands, if learners undertake all of the activities.

It is important that when learners are identifying properties, processes and materials in tasks 1 and 2 they are guided to choose from those listed in the ‘What you need to cover’ section of the Unit Specification.

The assignment should be spread across the teaching year, with time slots adding up to a total of 6 hours.

Task 3 requires the use of test equipment and this may present problems for some centres. A simple way to establish tensile strength is to use thin wire that is hung vertically and loaded with masses until it breaks. A scratch test based on Mohs’ scale would be sufficient for hardness testing.

The ‘Approaches to Assessment’ section of the Unit Specification gives more detailed teacher guidance. Note that the assessment grids have been split; ‘A’ relates to the marking of evidence presented as a portfolio and ‘B’ to that presented when the learner has carried out practical activities. Evidence of practical work should be in the form of witness statements, observation records, photographs and annotated test documentation, together with any written responses to activities, sufficiently detailed to be able to confirm to a moderator that the mark awarded by the assessor is accurate.

Guidance for Allocating Marks (reproduced from the Unit Specification) This section provides further guidance for the assessor on how to confirm marks within the best fit approach. This section should be referred to only once the preliminary judgement has been made by the assessor and is used to guide the assessor as to placement within the mark band.

Assessment Focus LO1

Mark Band 1-3

(1–9 marks)

One mark can be awarded for each of the four relevant material properties stated, e.g. tensile and compressive strength, hardness, toughness, etc.

One mark can be awarded for each of the three relevant property definitions. The definition need not be ‘textbook’ but must indicate a sufficient grasp of the key factors associated with each of the material properties defined.

One mark can be awarded for each of the two relevant explanations of how a material’s property affects its application.


Assessment Focus LO2.1

Mark Band 1-3

(1–7 marks)

The three ferrous metals chosen by the learner should be significantly different, e.g. low carbon steel, high carbon steel and grey cast iron, to demonstrate a knowledge of the range of ferrous metals and related forming processes. One mark can be awarded for each of the three relevant forming processes and engineering applications of ferrous metals given.

One mark can be awarded for each of the two appropriate descriptions of properties of the ferrous materials.

The justification should be in terms of the matching of material properties with the forming processes and applications. One mark can be awarded for each of two appropriate justifications.


Mark Band 1-3

(0–7 marks)

The three non-ferrous metals chosen by the learner should be significantly different, e.g. lead, copper and aluminium, to demonstrate a knowledge of the range of non-ferrous metals and related forming processes. One mark can be awarded for each of the three relevant forming processes and engineering applications of the non-ferrous materials chosen.

One mark each can be awarded for an appropriate description of the properties of two of them.

One mark can be awarded for each of two appropriate justifications, which should be in terms of the matching of material properties with the forming processes and applications.


Mark Band 1-3

(1–7 marks)

The two thermoplastic materials chosen should be significantly different in terms of their properties and applications, e.g. nylon, polythene, perspex, to demonstrate a knowledge of the range of thermoplastic materials. One mark can be awarded for each forming process and relevant engineering application for each material chosen, e.g. two different thermoplastics and one elastomer.

One mark each can be awarded for an appropriate description of properties of one thermoplastic material and one elastomer.

One mark can be awarded for each of two appropriate justifications, which should be made in terms of the matching of material properties with the forming processes and their applications.



Mark Band 1-3

(0–7 marks)

The two thermoplastic materials chosen should be significantly different in terms of their properties and applications, e.g. nylon, polythene, perspex, to demonstrate a knowledge of the range of thermoplastic materials. One mark can be awarded for each forming process and relevant engineering application for each material chosen, e.g. two different thermoplastics and one elastomer.

One mark each can be awarded for an appropriate description of properties of one thermoplastic material and one elastomer.

One mark can be awarded for each of two appropriate justifications, which should be made in terms of the matching of material properties with the forming processes and their applications.


Mark Band 1-3

(0–7 marks)

One mark can be awarded for each description of the abbreviated form used on engineering documents for each of the three engineering materials.

One mark each can be awarded for identifying two other materials specified on an engineering document.

One mark each can be awarded for identifying each of the two raw material forms and dimensional requirements.


Mark Band 1-3

(0–7 marks)

One mark can be awarded for identifying the engineering material used for each of the three engineering components. It is the outcome of the correct identification that marks can be awarded and not the process of visual or tactile inspection. However, information from books or the internet for example should not be used.

One mark each can be awarded for describing the properties of two of the identified engineering materials.

One mark each can be awarded for justifying the selection of the two identified engineering materials.



Mark Band 1-3

(0–7 marks)

Up to four marks can be awarded for the tests carried out on the engineering materials. Typically, one mark can be awarded for each of the two tests carried out on each of the two given engineering materials and for the correct evaluation of their mechanical properties.

Up to two marks can be awarded for comparing the mechanical properties of the two engineering materials.

Up to three marks can be awarded for selecting two tests to be carried out. Typically, one mark each can be awarded for the choice of each valid test and one mark for either one or both being the most significant mechanical property to test for the given material(s).


Unit 5: Introduction to Engineering Materials

Learning outcome Resource Comment

http://www.bbc.co.uk/schools/gcsebitesize/design/resistantmaterials/materialsmaterialsrev4.shtm A very accessible site for learners. It has a good combination of text, graphics and animations. It also has a short quiz.

LO1 http://www.design-technology.org/metalspresentation.ppt

A short downloadable PowerPoint presentation and quiz about products and the materials that they are made from.

LO2 http://www.iom3.org/education/sas.htm (schools affiliate scheme)

The Institute of Materials, Minerals and Mining (IOM3) is an excellent organisation to get involved with. The yearly subscription is £30 (2008). For this, you receive magazines, a set of large colourful wallcharts, which show where materials are used, and samples of materials. IOM3 also organises school challenges (national) and education programmes.

For more information, contact: Dr Diane Aston, Education Co-ordinator, The Institute of Materials, Minerals & Mining, Danum House, South Parade, Doncaster, DN1 2DY. Telephone 01302 320486 or email [email protected].


Learning outcome Resource Comment

http://www.bpf.co.uk/downloads/files/vacuumform1.swf

http://www.bpf.co.uk/downloads/files/InjectionMoulding.swf

http://www.bpf.co.uk/downloads/files/BlowMoulding.swf

Three very useful video clips from the British Plastics Federation. Ideal for learners to download and look at.

Vacuum forming

Injection moulding

Extrusion blow moulding

http://www.yorkshirelaser.co.uk/ - Useful site including a video clip showing laser cutting and profiling

LO3 http://www.tiniusolsen.com/

Tinius Olsen is a specialist manufacturer and supplier of tension and/or compression testing machines. This is a useful resource for teachers.


LO1, 2, 3

Books Godfrey, N. and Wallis, S., GCSE Engineering (Nelson Thornes, 2004) ISBN 0748785515 Higgins, R., Materials for Engineers and Technicians (Newnes, 2006) ISBN 0750668504 Timings, R.L., Engineering Materials, vol. 1 (Longman, 1998) ISBN 0582319285 Timings, R.L., Engineering Materials, vol. 2 (Longman, 2000) ISBN 0582404665 Boyce, Byrne, Darbyshire, Freeman, Meredith and Prodgers, Edexcel Diploma: Engineering Level 1 Foundation Diploma (Pearson, 2008) ISBN 978 0 435756 25 3

Recommended in the Unit Specification. These books are not mapped to the unit content but are a useful resource for teachers.

An excellent book to support the learner.

Unit 5: Introduction to Engineering Materials · PDF fileUnit 5: Introduction to Engineering Materials AS: ... Unit 7: Engineering the Future ... engineering materials AS 10

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