Investment Casting Process
The lost wax casting or casting, is a process of fusion also known as investment casting, with shapes almost finished; a shape that requires little step by step process of machining to achieve the requirements of tolerance. The shape can also be geometrically complex.
For each project, we start from a related model in lost wax obtained by injection into a mold or shell (fig.1).
The wax patterns are welded on supports wax forming the so-called cluster (fig.2).
Through subsequent dives of the bunch in ceramic bodies and resulting coatings with refractory materials, the ceramic shell is ottine (fig.3-4).
After the preparation of shells (fig.5), we proceed to the casting (fig.6).
After solidification and cooling, the cluster is released from the ceramic shell and then sanded and cut (fig.7). The ingates of casting are eliminated and the components thus obtained are thermally treated (fig.8) and checked (fig.9).
The stages of the casting process
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Die-pattern
1The patterns are obtained by injecting the semi liquid wax and the aluminium die.
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Pattern assembly
2The patterns complete with the gate are assembled around a central sprue, in order to form a type of cluster. On the wax cluster are put the ceramic coats.
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Ceramic shell creation
3The ceramic shell are made by special ceramic compound layers.
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Dewaxing
4After complete drying of the shell, we proceed to the elimination of the wax with a machine called autoclave.
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Shell heating
5The shell is emptied from the wax and baked at high temperature in a heating furnace.
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Casting
6The cast steel is poured inside the hot ceramic shell and consequently cooled.
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Knockout
7The ceramic shell is removed from the solidified steel cluster, then sand blasted.
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Finishing (Ingate removal)
8From the cluster are cut the pieces that are removed from the in gate, and processed with heat treatment and consequently machined.
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Inspection
9The final controls, analytical, dimensional, structural refer to the last phase of the production cycle, in order to grant the quality features requested by the customer.