Investment casting is a sophisticated metal forming process that generally involves using a wax pattern surrounded by a ceramic shell to form a mold. Once the shell is dry, the wax is melted out, and a ceramic mold is formed. Molten metal is poured into this mold to form a casting component, which may require additional machining after cooling to achieve the desired end results. Intricate shapes can be produced while maintaining extremely high degrees of dimensional accuracy and surface quality.

During the design process, investment casting can also be a useful option for prototyping purposes. Rapid prototyping, in particular, can help designers and engineers quickly gather feedback on the viability of a potential component, by creating a physical representation based on the initial drawings and designs. Corrections and revisions can then be made before the final production process begins. This article looks at the rapid prototype for investment castings.

What is Rapid Prototyping for Investment Castings?

Making prototypes is one of the building blocks of proving a design concept before going into full production. It helps to spotlight any potential problems and allows process engineers to make necessary adjustments. Rapid prototyping is a fast design process that involves creating an idea, quickly generating a prototype, and testing that physical part or model.

A hard-tooled wax pattern can be used for prototyping, but most modern foundries use printed 3D wax technology as a cost-effective and efficient solution for rapid prototyping, as well as small production runs. 3D printing can be used to develop complex investment castings which require design alterations, or are under a tight deadline. 3D printing eliminates the need for pattern tooling production; speeds up the casting process, design, and validation; and reduces overall development time when a hard tool is desired for scalable mass production.

The amount of precision in the prototype is based on the stage of development. A low-fidelity prototype might be created initially to study perceived advantages and potential problem areas, whereas a high-fidelity prototype is created as the design moves closer to that of finished investment casting.

What is the Rapid Prototype for Investment Castings Process?

In general, the steps in the rapid prototype for investment casting process are:

1. CAD Modeling: Advanced software is used to create a three-dimensional image of the proposed prototype.
2. Conversion: The CAD model is converted into a format which allows for virtual slicing, in order to study layers of the proposed design.
3. Slicing: An actual slicing of the digital file is performed, to provide cross-sectional contours for the model.
4. Model Fabrication: An initial prototype is printed by building the created layers on top of each other.
5. Post-Processing: The layering process results in a physical wax pattern, which is then cleaned and finished for progressing into the next steps of investment casting process.

3D printing is considered to be a layered additive form of rapid prototyping (RP). Other processes which may be used to create prototypes include subtractive, where material is removed through CNC processes.

What are the Benefits of Rapid Prototyping for Investment Castings?

The use of rapid prototyping for investment castings has a number of benefits:

• Reduced lead time for product development.
• Once finalized, the prototype design can be directly incorporated into a full production run.
• This is a highly-adaptable technology for product development situations where design alterations are needed, or for times when the project is under a tight development time window.
• Ideal for the development of complex parts.

The most important benefit of rapid prototyping for investment castings, though, is that it allows for the thorough testing of a product early in the design process. Multiple prototypes can be created for comparison purposes, design flaws can be recognized and corrected, and more refined casting options can be produced in a shorter period of time.

Learn More About Rapid Prototypes for Investment Castings

According to Roland Berger’s 2019 report, Impro is ranked among the Top 10 investment casting manufacturers in the world. Investment casting is Impro’s largest business segment and will continue to be our core business segment. If you are interested in finding more information about our rapid prototype for investment castings process and capabilities, please contact our team of experts today.