Metal Works 2, WASSCE (SC), 2018

Question 5

 

 

(a) Explain the following qualities of moulding sand as used in sand casting:

 

  1. compatibility;
  1. permeability;
  1. refractoriness.

(b) List three mechanical properties of ferrous metals.


(c) (i) What is coolant?


(ii) State two functions of coolant.

Observation

 

 

Most of the candidates could not explain the listed qualities of moulding sand. Parts (b) and (c) were well attempted by the candidates. The expected responses are as given below:

 

  1. Compatibility

It is the property of moulding sand that makes it adhere together without breaking during moulding. 

                                                                        

  1. Permeability

It is a property of sand which allows gases to pass through the sand during pouring of the molten metal. 

                                                                                                      

  1. Refractoriness

It is the property which enables sand to resist high temperature of the molten metal without breakdown or fusing.