System and method for manufacturing a part
A mould-forming and sacrificial materials are printed into a plurality of layers. The sacrificial material is removed to leave a void defined by a mould structure formed by the mould-forming material. The void is filled with a part-forming material to form the part defined by the shape of the mould structure. The mould structure is removed from the part to free the part from the mould structure. According to a further method, the part-forming material serves the purpose of supporting the mould-forming material and then forming the part. In this case, the part-forming material can be printed together with a mould-forming material as described above and are then heated to a temperature of approximately 700° C. to activate a binder and then heated to a temperature that melts the part-forming material.
1. A method of making a part comprising:
holding a mould-forming material in a first hopper;
holding a sacrificial material in a second hopper;
forming a first layer, the first layer including a first quantity of the mould-forming material from the first hopper and a first quantity of the sacrificial material from the second hopper;
forming a second layer on the first layer, the second layer including a second quantity of the mould-forming material from the first hopper and a second quantity of the sacrificial material from the second hopper;
removing the sacrificial material from the first and second layers to leave a void with a shape defined by a mould structure formed by the mould-forming material of the first and second layers;
filling the void with a part-forming material to form the part defined by the shape of the mould structure; and
removing the mould structure from the part to free the part from the mould structure.
2. The method of claim 1 , wherein the mould-forming material includes a granular material and a binder, further comprising:
heating the mould-forming material to activate the binder; and
allowing the mould-forming material to cool, whereafter the binder holds the granular material together when the sacrificial material is removed.
3. The method of claim 2 , further comprising:
positioning a plurality of heating structures around the mould-forming material, each heating structure including a heating element; and
providing a voltage over each heating element so that the respective heating element generates heat that heats the mould-forming material.
4. The method of claim 3 , further comprising:
connecting the heating elements in series.
5. The method of claim 3 , further comprising:
positioning a plurality of side refractory bricks around the heating structures.
6. The method of claim 3 , further comprising:
positioning a plurality of top refractory bricks over the mould-forming material.
7. The method of claim 2 , wherein the mould-forming material is heated to a temperature below a melting temperature of the sacrificial material to activate the binder.
8. The method of claim 2 , wherein the granular material is Zircon sand and the binder is sodium silicate.
9. The method of claim 1 , wherein the sacrificial material is removed by washing sacrificial material out of the void with water.
10. The method of claim 9 , wherein the sacrificial material is table salt.
11. The method of claim 1 , further comprising:
forming a third layer on the second layer, the third layer including a third quantity of the mould-forming material from the first hopper and a third quantity of the sacrificial material from the second hopper; and
removing the sacrificial material from the third layer to leave the void with the shape defined by the third layer.