Introduction of subject
The Manufacturing Process-1 subject is about various types of manufacturing processes such as welding, casting, machining which are used for production of various goods in industries and for other purposes. This subject provides knowledge about various types of techniques used in
various processes and for what type of products these techniques are suitable, for instance manufacturing of engine block is usually done by sand casting. This subject also throws light on the advantages and disadvantages of manufacturing processes in this subject. So the importance of this subject is that on basis of knowledge of various manufacturing processes and their merits and demerits we will be able to decide which manufacturing process is best suitable for us if we want to produce any product.
Unit-1(Foundry or Casting)
INTRODUCTION
Manufacture of a machine part by heating a metal or alloy above its melting point and pouring the liquid metal/alloy in a cavity approximately of same shape and size as the machine part is called casting process. After the liquid metal cools and solidifies, it acquires the shape and size of the cavity and resembles the finished product required. The department of the workshop, where castings are made is called foundry.
The manufacture of a casting requires:
(a) Preparation of a pattern,
(b) Preparation of a mould with the help of the pattern,
(c) Melting of metal or alloy in a furnace,
(d) Pouring of molten metal into mould cavity,
(e) Breaking the mould to retrieve the casting,
(f) Cleaning the casting and cutting off risers, runners etc., (this operation is called ‘fettling’), and
(g) Inspection of casting.
