When to Use Investment Casting Technique?

Learn about Investment Casting Technology

Investment casting technology is named after the process of "investing" or surrounding a pattern with refractory material. It became an increasingly popular casting process throughout the 20th century, but it was WWII that caused it to become a more mainstream industrial process. The demand for precision, net-shape manufacturing of special alloys using traditional techniques or those that were unable to be formed without extensive processing increased dramatically at this time.

Since then, investment casting technology has expanded to many commercial and industrial applications that require complexity, precision, and excellent cast surface smoothness. As a China stainless steel investment casting company, we believe that this can be a very efficient process because it requires less processing, saving labour costs, and wasting less alloy than other casting options due to less material used in the sprue and runner.

The Process of Investment Casting

Silica sol casting, also known as investment casting, is another metal casting process that can be mentioned in the paragraph. Like other casting processes, investment casting involves creating a mold into which molten metal is poured. However, the precision and surface smoothness obtained through investment casting technology are achieved through a series of precise steps. The first step is to produce an accurate metal mold, similar to the die-casting process. However, this mold is not used for casting metal but is instead used to create a wax mold that takes the shape of the finished component. The second step involves sacrificing the wax mold for each casting component, which is then replaced with a ceramic mold. The third step involves the pouring of molten alloy into the mold. The fourth step involves cooling and demolding. Finally, precision machining is carried out to remove any trace of the gating system and to improve the surface smoothness where necessary.

When is Investment Casting Suitable?

As with all casting processes, a balance needs to be struck between various parameters. Cost, smoothness, dimensional accuracy, schedule, yield, the alloy to be cast, and so on will all affect the decision of which casting process to choose.

The cost is impacted by the initial setup, which may be high for investment casting technology, but labour and material savings may exceed the initial cost in long-term operation. For smaller precision casting components, the ability to create multiple moulds and castings simultaneously can significantly reduce production costs. Component design can be improved through investment casting because extracting castings from moulds do not require draft angles (or draft), as in semi solid die casting. This also allows 90° angles to be incorporated into the design without shrinkage or further processing. The ability of investment casting to produce dimensionally accurate parts with cast surface finish capability compared to other casting processes can eliminate the need for further processing, which is a significant advantage and often a deciding factor.

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