Metals can be formed in a wide range of ways:-
Also by fabrication - by joining with
adhesives, fasteners (nuts and bolts, screws,rivets etc.), welding, soldering
(brazing,silver soldering, soft soldering).
Complex shapes can be produced using moulds:-
Metals can be cast into these moulds
using metal moulds is used for aluminium and zinc based
alloys which have a low melting point.
uses powdered or sintered metals which are compressed inside
the mould. The particles fuse together. Heating of the fused mass in
a furnace causes grain growth of the metal across the mass, giving much
greater strength. Carbide tips are formed by a sintering process.
These casting and moulding processes minimise waste.
is another method using moulds and dies with minimal waste.
A hydraulic press (a fly press
can be used on a smaller scale) can be used to deform metals using great
pressure and dies. Car body panels are pressed in this way. The press
will also cut parts out. A body panel will go through a series of pressings
on its way to completion.
Some sheet metal parts are simply pressed
(stamped out) to cut them out. The iron laminations used in transformers
and electric motors are stamped out using a cutting die.
Extrusion of hot metal
- through a die is similar to the method used for plastic extrusion but
here a hydraulic ram is used rather than a screw.