Question

The cooling characteristics of casting can be represented by the_____

(a) volume to surface area ratio

(b) product of volume and surface area

(c) surface area to volume ratio

(d) surface area to perimeter ratio

The question was asked by my college director while I was bunking the class.

Query is from Riser Design in section Pattern and Mould, Principles of Gating & Risering of Casting-Forming-Welding I

Answer 1

Right answer is (c) surface area to volume ratio

Easiest explanation: Solidification is basically occurred by losing heat from the surfaces and the amount of the heat is given by the volume of the casting, and the cooling characteristics of casting are given by the surface area to volume ratio. Riser is also similar to the casting in its solidification nature; hence the riser characteristics can also be given by the ratio of its surface area to volume.