chapter8: Material selection_Manufacturing Processes

In reference to Figure 8.1, identify which components are:

• moulded

• stamped

• extruded

Explain why copper is used in the manufacture of the parts labelled C, D, and E in Figure 8.1.

Provide three reasons for using ABS to manufacture the power supply enclosure shown in Figure 8.1.

Which of the following best describes composite materials and how they differ from metals and ceramics?

• Composite materials are made from two or more constituent materials with significantly different physical or chemical properties.

• Composite materials are similar to metals in terms of their chemical composition and usage.

• Composite materials and ceramics are indistinguishable in terms of their properties and applications.

• Composite materials are generally less durable than metals and ceramics.

What is the important difference between thermoplastics and thermosetting plastics and how does this impact on what they can be used for?

• Thermoplastics can be remelted and reshaped, useful for recycling; thermosetting plastics cannot, making them suitable for heat-resistant applications.

• Thermosetting plastics can be remelted and reshaped, useful for recycling; thermoplastics cannot, making them suitable for heat-resistant applications.

• Both thermoplastics and thermosetting plastics can be remelted and reshaped, making them equally useful for all applications.

• Neither thermoplastics nor thermosetting plastics can be remelted, limiting their use in recycling and heat-resistant applications.

You need a material to line the inside of a furnace. What class of material would be suitable and why?

• Metals, because they can withstand high temperatures.

• Ceramics, because they can withstand very high temperatures and are non-reactive.

• Plastics, because they are cheap and readily available.

• Wood, because it is easy to shape and fit inside any furnace.

Describe four different forms in which engineering materials can be supplied.

Which materials would be suitable for the manufacture of a roller bearing?

• Wood and plastic

• Steel and ceramics

• Glass and paper

• Rubber and leather

Which materials would be suitable for the manufacture of a damp-proof membrane?

• Polyethylene sheeting

• Bituminous material

• Liquid coatings

• None of the above

Which materials would be suitable for the manufacture of a 'non-stick' coating for the plates of a sandwich toaster?

• Teflon

• Stainless steel

• Aluminum

• Ceramic