材料及其加工特性：练习题

Which of the following materials is correctly classified as a hardwood within the AQA specification?

A designer is selecting a material for a child\'s stacking toy that requires high impact resistance and the ability to be injection moulded in bright colours. Which thermoforming polymer is most suitable for this application?

An engineer needs to select a metal for a high-speed drill bit that will maintain its hardness even when heated to high temperatures during heavy use. Which of the following is the most appropriate material?

When a metal is being processed by being hammered or rolled into a thin sheet without cracking, which working property is it demonstrating?

In the context of material management and efficiency, a designer uses tessellation or nesting when planning a layout for a CNC router. What is the primary purpose of this technique?

A manufacturer is choosing a material for a high-end kitchen utensil. Compare the working properties of stainless steel and cast iron in terms of their thermal conductivity and corrosion resistance.

A product requires a material that can be deformed under compressive force without cracking and return to its original shape. Identify the specific mechanical property required and explain why a thermoforming polymer like polypropylene (PP) is more suitable for this than a thermosetting polymer.

Designers must choose materials based on their physical and mechanical properties.

(a) A manufacturer is designing a new handle for a high-quality kitchen cooking utensil. Suggest a suitable hardwood and justify your choice based on its working properties. [3]
(b) Why might a designer choose Urea-formaldehyde for an electrical fitting instead of a thermoforming plastic like Polypropylene? [3]

Properties of materials can be modified to suit specific purposes.

(a) Describe the process of annealing and explain why it is used when working with metals. [3]
(b) Explain how the addition of UV stabilizers affects the lifespan of polymer-based garden furniture. [2]
(c) Why are flame retardants essential additives in the production of synthetic textiles for public transport seating? [2]