Introduction & basic materials used in foundry:
Introduction:
Definition, Classification of manufacturing processes. Metals cast in the foundry-classification, factors that determine the selection of a casting alloy.
Introduction to casting process & steps involved:
Patterns:
Definition, classification, materials used for pattern, various pattern allowances and their importance.
Sand moulding:
Types of base sand, requirement of base sand. Binder, Additives definition, need and types; preparation of sand moulds. Melding machines- Jolt type, squeeze type and Sand slinger.
Study of important moulding process:
Green sand, core sand, dry sand, sweep mould, CO2mould, shell mould, investment mould, plaster mould, cement bonded mould.
Cores:
Definition, need, types. Method of making cores,
Concept of gating (top, bottom, parting line, horn gate) and risers (open, blind) Functions and types.
MELTING & METAL MOLD CASTING METHODS:
Melting furnaces:
Classification of furnaces, Gas fired pit furnace, Resistance furnace, Coreless induction furnace, electric arc furnace, constructional features & working principle of cupola furnace.
Casting using metal moulds:
Gravity die casting, pressure die casting, centrifugal casting, squeeze casting, slush casting, thixocasting, and continuous casting processes.
SOLIDIFICATION & NON-FERROUS FOUNDRY PRACTICE:
Solidification:
Definition, nucleation, solidification variables. Directional solidification-need and methods. Degasification in liquid metals-sources of gas, degasification methods.
Fettling and cleaning of castings:
Basic steps involved. Sand Casting defects- causes, features and remedies. Advantages & limitations of casting process
Nonferrous foundry practice:
Aluminium castings - advantages, limitations, melting of Aluminium using liftout type crucible furnace. Hardeners used, drossing, gas absorption, fluxing and flushing, grain refining, pouring temperature. Stir casting set up, procedure, uses, advantages and limitations