Green Sand
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Investment
|
Die
|
Molten metal is poured
into a non-reusable sand mold.
|
Molten metal is poured
into a non-reusable
preheated ceramic mold.
|
Molten metal is forced
into a reusable mold and
held under pressure until
solidification.
|
Process Steps
|
Process Steps
|
Process Steps
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1. Create mold using a
mold pattern
2. Heat metal and pour into
mold
3. Wait until solidification,
remove from mold
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1. Wax patterns prepared
from aluminum dies
2. Wax patterns are coated
with ceramic
3. Wax is melted from
ceramic mold and mold
is fired
4. Mold is heated and
molten metal is poured
|
1. Introduce molten metal
into ram
2. Ram forces metal into
mold chamber
3. After minimal cooling
mold opened and part
ejected
|
Characteristics
|
Characteristics
|
Characteristics
|
* Tolerances of +/- 1/8 in.
usual, tolerances of +/-
1/16 in. can be reached
* Surface finish 200 - 600
ui typical
* Sand contains binding
material
* Produces rough textured
finish
|
* Tolerances of +/- 0.005
reached
* Surface finish 63 - 125 ui
typical
|
* Tolerances of +/- 0.0005
reached
* Surface finish 32 - 63 ui
typical
* Fastest casting method
|
Advantages
|
Advantages
|
Advantages
|
can use any metal that can be
melted, can produce many
different shapes, sizes
|
patterns can be clustered to
increase production rate,
volatile metals can be poured
in a vacuum, mold making
can be automated,
small and intricate parts can
be produced
|
fast, excellent detail,
required minimal machining
|
Limitations
|
Limitations
|
Limitations
|
produces parting line in
workpiece; sprues, risers,
runners must be removed
|
more time required to make
mold
|
may produce small amount
of flash, leaves ejection pin
marks
|
Typical Applications
|
Typical Applications
|
Typical Applications
|
engine blocks, gear blanks
|
gears, intricate parts, just
about anything!
|
toys, high production parts
|
