1.1 Material Selection — Part 1: Selecting materials

What are the three main considerations when selecting a material?

• Will it meet the performance requirements?

• Will it be easy to process?

• Does it have the correct aesthetic properties?

What functional properties or requirements might be considered when selecting a material?

• Hardness

• rigidity

• weight

• flexibility

• buoyancy

• colour/texture

• environmental suitability and stability.

Why is correct costing and forecasting fundamental when manufacturing a product?

Costs are incurred not only when buying the material, but also during machining, joining, finishing and other stages of manufacture.

Why might an expensive material still be selected?

An expensive material may be justified if it is easier to machine, process or work with, potentially reducing other manufacturing costs.

What are the common scales/types of production?

• Continuous production

• mass production

• batch production

• one-off production

Why must the scale of production be considered when selecting a material?

The material must be suitable for the manufacturing process and quantity required. A material/process suitable for one-off production may not be appropriate for mass production

In what forms are materials commonly supplied?

Materials are generally supplied in standard forms, shapes and sizes

What is the likely effect of using non-standard materials or sizes?

They are likely to increase the cost of raw materials

What standard forms can metals be supplied in?

• Sheet

• plate

• box section

• tube

• rod

• and coils of wire.

Why does the choice of joining technique depend on the materials being joined?

Different materials require different joining methods, and the method also depends on whether the joint needs to be permanent or semi-permanent.

What is a permanent joint?

A joint that cannot be reversed/disassembled without causing damage to the material or product.

What is a semi-permanent joint?

A joint that can be disassembled without damaging the materials.

What is the difference between brazing and soldering?

They are similar joining processes, but soldering is carried out at lower temperatures than brazing.

Give three examples of adhesives named by CCEA.

• PVA

• contact adhesive

• epoxy resin.

Name four common wooden frame joints

• Butt joint

• halving joint

• mortise and tenon joint

• dovetail joint.

Where are knock-down fittings predominantly used?

Self-assembly products such as flat-pack furniture