材料的性能特性：练习题

Which performance characteristic describes a material's ability to be permanently deformed by compression without rupture, such as when being hammered into thin sheets?

A manufacturer is producing a high-pressure hydraulic valve component using Cast Iron. During the design phase, the engineer must account for the specific performance characteristics of this material compared to mild steel. Which of the following best describes the primary limitation of cast iron when subjected to sudden impact loads in a commercial setting?

An aerospace engineer is comparing the malleability and ductility of Duralumin against pure Aluminium for a specific fuselage skin component. Why is Duralumin often preferred in this context despite being more difficult to work initially?

A designer is selecting a polymer for a garden chair that must withstand prolonged exposure to sunlight and variable weather conditions without becoming brittle or losing its structural integrity. Which performance characteristic is the primary consideration for ensuring the chair remains functional over several years?

A manufacturer is comparing the performance of Polyethylene (PE) and Urea Formaldehyde (UF) for use in high-temperature electrical fittings. While both must be electrical insulators, the component must not soften or change shape if the internal temperature increases significantly. Which combination of performance characteristics and material classification makes Urea Formaldehyde the more appropriate choice?

State the term used to describe a material's ability to withstand scratching, surface wear, or indentation, and name one metal from the specification that typically exhibits this property to a high degree.

A designer is selecting a material for a high-performance bicycle frame. Explain why toughness is a more critical performance characteristic than hardness for this specific application.

Analyze why toughness is the essential performance characteristic for the casing of a handheld power tool, and explain how it differs from strength in this context.

A designer is selecting materials for a high-performance mountain bike frame. The frame must be able to withstand sudden impacts without breaking and maintain its shape under heavy loads. Two materials under consideration are 6061 Aluminium alloy and Carbon Fibre Reinforced Plastic (CFRP).

(a) Compare the toughness and elasticity of these two materials in the context of mountain bike performance. (4 points)

(b) Explain how the durability of the aluminium alloy might be affected over time when exposed to the outdoor environments typically encountered in mountain biking. (1 point)

An engineer is testing the performance characteristics of various materials for use in a new aerospace heat shield. The shield must withstand extreme temperatures and maintain its structural integrity.

(a) Compare the suitability of thermo-ceramics and stainless steel for this application, referring specifically to their conductivity and toughness. (4 points)

(b) Define malleability and ductility. Explain why a material with high ductility is preferred for components that must be drawn into thin wires for the aircraft's internal sensors. (3 points)