Heat treatments and alloying: Practice Questions

Which polymer processing method is most suitable for the mass production of hollow plastic containers, such as shampoo bottles?

In the production of high-end commercial packaging, a designer wants to create a metallic, reflective finish on specific areas of a folding box board without using a full foil laminate. Which finishing technique is most appropriate for this localized application?

In the industrial manufacture of high-precision metal components, a process is required to relieve internal stresses and soften the metal for further machining without changing its chemical composition. Which heat treatment process should be selected?

A precision engineering firm uses go and no-go gauges to verify the dimensions of a batch of stainless steel shafts. If the tolerance is defined as \(25mm \pm 0.05mm\), how are these specialist tools applied to ensure quality control?

Calculate the accuracy of a measurement taken with a vernier calliper if the main scale is graduated in millimeters and the vernier scale has 50 divisions equating to 49mm. What is the smallest increment (resolution) this tool can reliably measure?

Contrast die casting and sand casting in terms of their suitability for high-volume manufacturing and the resulting quality of the surface finish.

Explain why anodising is classified as a "conversion coating" and how this process differs from electro-plating in terms of the relationship between the coating and the base metal substrate.

The selection of manufacturing processes is critical to the durability and performance of metal products. A company is producing high-tensile steel bolts for use in bridge construction.

(a) Explain the hardening and tempering heat treatment process. In your answer, clarify why tempering is necessary after the steel has been hardened. (4 points)

(b) To prevent degradation of the steel bolts in an outdoor environment, the designer specifies galvanisation. Describe the process of galvanisation and explain why it provides better long-term protection than a standard paint finish. (3 points)