YOUR AIMS
On completion of this lesson, you should be able to:
- identify the advantages and limitations of powder technology manufacturing routes
- select powder manufacturing routes for metals and ceramics
- understand how to control particle characteristics to optimise component manufacture
- describe some ceramic shaping processes.
ASSESSMENT QUESTIONS
1. (i) Discuss the advantages and limitations of chemical reduction for metal powder production.
(ii) Choose a method for the manufacture of high purity copper powder which has good pressing qualities.
2. Why are powder technology processing routes being increasingly used for the manufacture of engineering components?
3. (a) Outline the basics of atomisation processes for the manufacture of metallic powders and explain how the following affect particle characteristics:
(i) liquid metal velocity
(ii) atomising fluid velocity
(iii) droplet size.
(b) (i) What are the reasons for the synthetic manufacture of ceramic powders?
(ii) Outline a process for the manufacture of fine alumina powders (particle sizes of 50 - 100 × 10-10 m diameter).
(iii) What are the advantages and problems of subsequently using the powder from (ii) for the manufacture of alumina components?
4. Describe, with reasons, the ideal powder particle characteristics for the shaping of 'green' ceramic components by:
(a) slip casting
(b) die/isostatic pressing.