Question 4
(a)(i) Sketch a sectional view of a sand mould.
(iii) Label the following parts on the sketch in 4(a)(i)
(1) cavity;
(2) runner;
(3) riser;
(4) vents.
(b) State the function of the following:
(i) pattern;
(ii) vents.
(c)State two faults which may result from poor ramming in sand casting.
Observation
Most of the candidates who attempted this question could not provide the required responses to parts (a) and (b) of the question.
The required responses to these parts are:
(a) The Sectional View of a Sand Mould with Four Labelled Parts
(b)(i) The Functions of Pattern
- It is used for forming cavity in sand moulding.
(b)(ii) The Functions of Vents
- Vents are provided to allow the escape of gases from the molten metal during solidification.