Custom Investment Casting of Ductile Cast Iron

China OEM custom ductile cast iron castings by lost wax investment casting process. Ductile iron, which is also known as ducitle cast iron, nodular iron, spheroidal graphite iron, spheroidal graphite cast iron, or just SG iron for short. When graphite is present as small, round, and well-distributed particles, its weakening effect is small and such cast irons would have higher ductility. This type of cast iron is called ductile or nodular iron or spheroidal graphite or simply SG iron. This form of graphite can be achieved by adding elemental magnesium or cerium or a combination of the two elements to molten cast iron. Magnesium is added in quantities of 0.07 to 0. 10% followed by the addition of ferro-silicon to promote graphitization. During solidification, magnesium helps in the distribution of graphite throughout the metal.

Ductile iron has better strength-to-weight ratio, better machinability and higher impact value. Moreove, the ductile iron components are produced by casting process wherein better control of component shape can be achieved compared to drop forging. Thus, many a component such as crank shafts and connecting rods manufactured usually by drop forging is increasingly being replaced by ductile iron castings.

Capabilities of Investment Casting Foundry:
• Max Size: 1,000 mm × 800 mm × 500 mm
• Weight Range: 0.5 kg - 100 kg
• Annual Capacity: 2,000 tons
• Bond Materials for Shell Building: Silica Sol, Water Glass and their mixtures.
• Tolerances: On Request.

Advantages of Investment Casting Components:
- Excellent and smooth surface finish
- Tight dimensional tolerances.
- Complex and intricate shapes with design flexibility
- Capability to cast thin walls therefore a lighter casting component
- Wide selection of cast metals and alloys (ferrous and non-ferrous)
- Draft is not required in the molds design.
- Reduce the need for secondary machining.
- Low material waste.

Casting Tolerance Could Reached by Investment Casting:
According to the different binder materials used for making the shell, the investment casting could be divided into silica sol casting and water glass casting. The silica sol investment casting process have better Dimensional Casting Tolerances (DCT) and Geometrical Casting Tolerances (GCT) than water glass process. However, even by same casting process, the Tolerance Grade will be different from each cast alloy due to their various castability. Our foundry would like to talk with you if you have special request on the required tolerances. Here in the following are the general tolerances grade we could reach both by silica sol casting and water glass casting processes separately:
✔ DCT Grade by Silica Sol Lost Wax Casting: DCTG4 ~ DCTG6
✔ DCT Grade by Water Glass Lost Wax Casting: DCTG5 ~ DCTG9
✔ GCT Grade by Silica Sol Lost Wax Casting: GCTG3 ~ GCTG5
✔ GCT Grade by Water Glass Lost Wax Casting: GCTG3 ~ GCTG5