Question 4
(a) Explain the following foundry terms:
(i) Core print;
(ii) Cavity.
(b) State two qualities of a moulding sand.
(c) (i) Sketch a carburizing flame
(ii) Label two part of the carburising flame sketched in 4(c)(i).
Observation
Most of the candidates who attempted this question could not provide the required responses to part(b) of the question.
The required responses to these parts are:
Stating two qualities of moulding sand
- Refractoriness – Ability to withstand heat
- Permeability – Porous to allow gases to escape
- Compactibility – Ability to be pressed in place and retain the shape
- Collapsibility – Ability to break down mould after use
- Reusability – Ability to use moulding sand all over again