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Metalworking
involves several different phases or processes. They
include:
• Marking Out
• Casting
• Forming
• Cutting
• Joining
Below, we’ll look at each of these processes in
detail.
Marking Out
Marking out, which is sometimes also referred to as
layout, is the process of taking an engineer’s
design plan to the shop and preparing the project for
manufacture.
Casting
Casting is a process by which metal is poured into a
mold and therefore takes on the shape of the mold. There
are several different types of casting used in different
projects and processes. The various types of casting
are:
• Investment casting
• Centrifugal casting
• Die casting
• Sand casting
• Shell casting
• Spin casting
Forming
Forming is a process by which the shape of a metal piece
is changed without dissolving or taking away from the
actual metal used in the piece. A combination of heat
and mechanical forces are used to achieve results in
forming.
There are different types of forming. They are:
• Bulk forming
• Sheet forming
Bulk forming requires heat, which softens the metal
and makes it more receptive to mechanical force. Once
the piece is heated up, mechanical processes are then
used to re-form the piece.
Sheet forming does not use heat and rather uses mechanical
force to re-shape the piece while it is at room temperature.
Cutting
Cutting is, to put it simply, the process by which the
shape or size of metal is changed by making incisions
in the metal and removing particular pieces from it.
Cutting results in two pieces of metal - one that will
be discarded or repurposed, and one that is part of
the finished product.
There are different types of cutting processes, including:
• Machining: a
process that produces chips
• Burning: a process
through which an oxidized kerf is used to cut metal
Drilling a hole into a piece of metal would be considered
machining, or a chip-producing process. Utilizing a
torch in order to burn through material and separate
it would be an example of burning.
Joining
Joining is the process by which metal is brought together.
Welding is a particularly prevalent approach in joining.
Welding uses heat to coalesce two metals together using
heat. Sources of heat for welding range depending on
the project. Some common heat sources for welding are:
• Friction
• Ultrasound
• Electron beam
• Laser
• Electric Arc
• Gas Flame
Brazing and soldering are also methods for joining.
In brazing, a filler metal is heated up to melting point
and is then drawn into a capillary i the metal piece.
The filler metal solidifies in the capillary creating
a joint. Soldering is a similar process, however it
is completed at a lower temperature than brazing.
Finally, riveting is an ancient process for joining
that is still used today. Riveting involves the use
of a two-headed and unthreaded bolt, which joins two
pieces of metal together. In order for this system to
work, a hole must b drilled or punched into the metal
prior to installation. Permanent links are created by
forming dies or utilizing hammers. |
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