Wax
Cell
1.Tooling
Initially, before the casting process begins, an injection die
is constructed to produce precise wax patterns.
2.Pattern Injection
A specially formulated wax is injected into a die to produce the
pattern for the part.
3.Pattern Assembly
The individual wax patterns are assembled onto a wax sprue to
form a mold or tree.
Shell
Building
4.Shell Building
A ceramic mold is created by dipping or “investing” the assembled
patterns in liquid ceramic slurry, draining, and then coating
with a dry “stucco” sand. After drying, this process is repeated
several times until a specified shell thickness results.
5.Dewaxing and Firing
The wax is melted out with steam heat in an autoclave and is recycled.
Firing at 1800 degrees Fahrenheit fuses the ceramic particles
so the mold can withstand the pressure and temperature of the
molten metal. It also removes all traces of organic materials.
Casting
Cell 
6.Casting
Molten metal is poured into the pre-heated molds. Typical pouring
temperatures are approximately 3000 degrees Fahrenheit for steel.
The investment casting process is unique in the broad range of
alloys that can be cast.
7.Knockout
The ceramic shell is removed from the metal mold by vibration.
8.Casting Removal
Metal casting are removed from the runner using abrasive wheel
cutoff saws.
Finishing Cell

9.Gate Grinding
The material protrusion left from the gate, called the gate witness,
is ground to print specification using a fixture for repeatability
and efficiency.
10.Finished Castings
The final cleaning operation is performed using a blast with abrasive
grit or steel short. This blasting produces a surface finish of
90-125 microinch Ra
11.Complete-to-print
Typically, investment casting can provide a cast shape that requires
no secondary operations. If premium tolerances, surface finish,
or coatings are required, Lianmei can supply complete-to-print
components.
|