METAL PROCESSING TECHNIQUES

1. PRESENTED BY:
2017-BME-12
2017-BME-34
2017-BME-45
2017-BME-46

2. IMPORTANT POINTS
Definition
Processing
Factors Affecting
Operation On Metals
Recycling

3. 1. Definition:
Metals processing refers to the industry of recycling
scrap metals and metal product for reuse by the
metal manufacturing industry. When major
appliances become unstable foe their original
purpose, these items are often designated as scrap or
salvage i.e. processed in metal processing plants.
2. Processing:
The metal processing industry cover many fields of
metal recycling. These areas include sheet metal
processing, steel processing and noble metal
processing, among other fields.

4. 3. the metal is heated. A grain can grow larger by
atoms migratinFactors Affecting:
 Grain Size Effect
 Quenching And Hardening
 Cold Working
 Grain Size Effect:
It has long been know that the properties of some metals
could be changed by heat treating. Grains in the
metal tend to grow larger as grow from another
grain that may eventually disappear .

5. Dislocation cannot cross grain boundaries easily, so the size
of grain determine how easily the dislocations can move.
Quenching And Hardening:
There are many ways in which metals can be heat
treated. Annealing is the softening process in which
metals are heated and then allowed to cool slowly.
Most steels may be hardened by heating and
quenching. This process was used quite early in the
history of processing steel.
Quenching results in the metal that is very hard but also
brittle.

6. Cold Working:
Because plastic deformation results from the movement
of dislocations, metals can be strengthened by
preventing this motion. When a metal is bent or
shaped, dislocations are generated and moved. As the
dislocations in the crystal increases, they will get
tangled or pinned and will not be able to move. This
will strengthened the metal, making it harder to
deform. This process is known as cold working. At
high temperature, the dislocations are rearrange, so
little strengthening occurs.

7. Operations On Metals
There are many operations but some are discussed here:
Bending
It is a metal forming process in which force is applied to the
piece of sheet metal, causing it to bend at an angle and
form it to desired shape.
Bending Types
 V Bending
 Edge Bending

8.  V Bending
The sheet metal blank is bent between a V-shaped and
die. If the punch does no force the sheet to the bottom
of the die cavity, leaving space or air is called air
bending.
 Edge Or Wipe Bending
It requires the sheet to be held against the wipe die by a
pressure pad. The punch then press against the edge of
the sheet that extend beyond the die and pad. The
sheet will bent against the radius of edge of wipe die.

9. Shearing
It is defined as separating the material in to two parts. It
utilizes hearing force of cut sheet metal.
Blanking
A piece of metal removed from a larger piece of stock.
This removed piece is not scrap, it is the useful part.
Fine Blanking
A second force is applied underneath the sheet, directly
opposite the punch by a ‘cushion’. This technique
produces the part with better flatness and smoother
edge.

10. Punching And Piercing
The typical punching, I which a cylindrical punch
pierces a hole in to sheet.
Trimming
Punching away excess material from the perimeter of
the parts, such as trimming the flange from the drawn
cup.
Parting
Separating a part from the remaining sheet, by punching
away the materials between the part.
Slitting
Cutting straight lines in the sheet. No scrap materials is
produced.

11. Lancing
Creating the partial cuts, so that material is not
removed. The material is left attached to be bent and
form a shape, such as tab, vent or louver.
Notching
Punching the edge of the sheet, forming a notch in the
shape of a portion of punch.
Perforating
Punching a close arrangement of a large number of
holes in a single portion.

12. Nibbling
Punching a series of small overlapping slits or holes
along a path to cut out a larger contoured shape.
Cut Off
Separating a part from the reading the sheet without
producing any scarp.
4. Recycling
Some metals, such as aluminum, can be recycled an
infinite number of times with minimal losses of
metals. This makes scrap processing a very
environmentally sound industry