When to Use Investment Casting?

When you have a project of metal parts at hand, you may be puzzled at the production process. As an investment casting expert, we are familar with investment casting technique, and also well know other metalworking process. We can help you to decide whether your component is a good design to be investment cast. You just need to send us the drawing or old sample, then we can help you to select a right solution, and offer you our best prices for tooling and castings.

But if you have decided to use investment casting to produce your part. Here is a quick list of some main characteristics which are ideal to make your part with investment casting …

when to use investment casting

My part weighs between 0.5 lbs. and 120 lbs., and measures less than 100″ in all directions.

Although we have the capability to cast parts over 200 lb, most of the time, we specilise in making investment castings that tend be much lighter and smaller than that. Because it will be difficult to achieve accurate investmet castings if the part is too large. Also, both the tooling cost and machining cost will be much more than small parts. But it does not mean we can not make large parts by casting. Sand casting is often a better choice in those components. So it is fact that investment casting is more ideal for smaller components. With Investment casting, the dimensional accuracy of the products is quite good, the tooling can be produced with affordable cost, and the mounting and gating can generally be done with little issue.

I need to make the part more than just once.

When investment casting, the production process seems a repeating process. It is best suited when the component is required time after time. You have the option to order in small volume or large volume, however, as we all know that, the finished investment casting part is the replica of a wax pattern that by injecting wax into casting moulds. So if you just need the parts only once, it is not cost effective for you due to the charged design and tooling cost. Of course, it is NOT uncommon for our customers to purchase a small lot size of a production casting, sometimes as few as 200pcs at a time, since we specialize in, and welcome orders of small to medium run sizes, however our customers generally order these small lots on an ongoing basis.

The part I am considering requires high precision and I want to reduce my costs.

When it comes to high precision, investment casting is second to none. As machining from bars directly will cause large waste of material and high machining cost is required. Forging may meet your demands, but the tooling cost is too high if the quantity is not large. However, Investment casting, which also knows as precision casting, takes advantage of making components with complex shapes. And it can help you to obtain precise dimensions as tight as CT5. The most distinctive advantages of an investment casting over other processes is the ability to not only from material grades, but also can make according to your given material composition. For too tight tolerances that beyond investment casting capabilities, we just need to leave little machining allowance, the even if machining is avoidless, the cost is relatively much lower than other processes.

The parts I am seeking that have complex internal details

Investment Casting can meet your demands when the parts have complex internal strcutures. That is because the “mold” that is used to pouring molten metal is made from ceramic, and it is easy to break away after solidification and cooling. The internal detail of the wax pattern which was coated to form the ceramic shell can easily be achieved through innovative tooling, soluble wax coring, or ceramic coring. Therefore, there is no limit to the internal detail of a component in investment casting. So it is necessary to have a detailed understanding on investment casting process. Otherwise, the designer of a part or purchaser may give up ideal internal details because they think there is no practical way to meet the effect of complex inners.

Current used manufacturing process is too expensive and there is inconsistency from part-to-part.

An investment casting should be considered as the superior option when it comes to improving the generally “rough” characteristics of current products, which is made by sand castings, forgings, or weldments. Investment casting mights lightly cost more per unit as it gets comparatively more processing involved. Compared to sand casting (refer to investment casting vs sand casting) or forgings, investment casting has unbelievably smooth surface and no draft angles or parting lines, which make it ideal to replace obvious manufacturing process. Even if investment casting cost is higher, it is still worthly as it can improve surface without machining operations. Also parts by investment casting will be consistent.

Difficulty finding an ideal raw material stock size for the specialty alloy.

One of the key step of investment casting process is to melt ingots into liquid status and pour it into ceramic shell. So One of the main benefits of investment casting, is that most alloys can be melted, and cast, providing a near-net shape component. Investment castings are not restricted when we can not find raw material from material market. We make parts with given material composition by adding required elements. So even if the quantity is small, investment casting can also be used for your parts. However, like forging or machining, the material have to be ordered from material factory, even if the material factory can customize the material for you, it is not be a good choice and is costly if it is small volume production. With investment castings, the near-net shape provides for minimal up-front material cost, minimal material loss through machining, and the ability to cast to size many details and dimensions for hard to machine alloys.

Of course, although there are lots of investment casting advantages, it does not mean it is almighty. We can not use investment casting in below conditions:

  • The part can be easily machined from raw material.
  • The structure of the part is quite thin or quite long.
  • Too small or too large component
  • Material used is cast iron, aluminum or other alloys.
  • And so on….

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