Investment Casting vs. Die Casting: Which Is Right for Your Application

Casting is an ancient manufacturing technique that dates back to the 1890s. Two common casting techniques available today are investment casting and die casting. Although these technologies share the same basic principles, investment casting has specific differences from die casting. Investment casting involves injecting wax into an aluminum mold cavity. The die casting process, on the other hand, forces molten metal under high pressure into the mold cavity.

This article will provide an overview of these technologies, including their main advantages. You'll also learn the differences between investment casting and die casting to help you choose the best option for your project.

Detailed Comparison: Investment Casting Vs Die Casting

work process

The precision custom casting process begins with making a wax pattern that is used to produce the desired end product. The operator then attaches wax to the base of the sprue and repeatedly dips them into the ceramic mold. After the ceramic hardens and takes the shape of the casting, the mold is heated to melt the wax. The operator then fills the mold cavity with molten metal. As the metal cools and solidifies, the mold is broken to remove the casting.

Die casting, on the other hand, involves injecting liquid metal into a mold cavity under high pressure. Technicians use hardened steel tools to create a mold cavity tree with the desired product shape. The molten metal is then placed on the sleeve and a piston is used to force it into the mold cavity. This piston applies continuous pressure as molten metal fills the mold. Once this metal cools, operators remove the tree and remove the components. This part usually requires secondary machining to complete.

Casting material selection

Investment casting is suitable for a wide range of metals and works perfectly with both ferrous and non-ferrous metals. This casting process can be used with metals such as stainless steel, copper, aluminum, zinc, etc. Additionally, it can cast difficult-to-machine alloys.

Die casting, on the other hand, is ideal for non-ferrous metals. These metals include aluminum, zinc, copper, lead and magnesium alloys. Therefore, investment casting offers a wider choice of materials than die casting.

design complexity

When comparing investment casting vs. die casting, the geometry of your design is critical. Investment casting enables more precise dimensions, thin-walled parts and other complex geometries. This technology provides greater design flexibility, allowing you to incorporate various design features and cast complex parts.

Although die casting can produce larger parts and good dimensional results, it does not offer the same level of sophistication as investment casting.

Part size

Investment casting can accommodate parts from 0.02 kg to approximately 100 kg. However, there are some limitations on part size for this process. This is because the wax pattern needs to be safely gated to the tool gate to ensure repeated dipping in the refractory slurry.

Die casting, on the other hand, can produce larger parts with fewer size restrictions. You can basically get any past size through this process. However, making large parts with die casting will require larger tooling and unit costs.

surface treatment

When you compare die castings to investment castings, you will find that investment castings have a better surface finish than die castings. The standard precision tolerance for this process is IT5-6 and you can get up to 125 microfinishes. This reduces or eliminates the need for secondary processing.

The die casting surface treatment is also good enough. However, parts made with this process require additional processing to achieve the desired results.

Production

Cuestom Investment casting is better suited for low-volume production, typically less than 10,000 pieces. In contrast, die casting is ideal for high-volume projects and high-volume production of more than 10,000 pieces, as it can produce 100 to 2000 parts per hour. While tooling costs can be high, a single mold can produce up to a million components. Additionally, the process ensures excellent repeatability and consistency, making it ideal for large-scale runs.

tolerance

Both investment and die casting can produce good and tight tolerances. However, the tolerance capabilities of the casting process depend greatly on the type of material used and the shape of the part.

The general rule is that the smaller the part, the greater the dimensional accuracy. Therefore, investment casting has tighter tolerances (approximately +/-0.005 inches) when it comes to smaller components. However, large investment castings often lose some dimensional accuracy. In this case, die casting would be a better choice for larger parts as it can offer standard tolerances of +/-0.010 inches and precision tolerances of up to +/-0.002 inches.

cycle

Traditional investment casting is very time consuming and requires some labor and casting time. Conventional die casting, on the other hand, can produce up to 3 to 4 shots per minute. Multi-sided die casting can produce more than 45 shots per minute, and even 100 shots per minute for smaller parts. Die castings are usually produced completely automatically, requiring little human involvement.

Investment Casting vs. Die Casting: Which Is More Cost-effective?

When comparing the production costs of investment casting versus die casting, throughput plays an important role. If your production volume exceeds 10,000 pieces, die casting will be more cost-effective than investment casting. Because die casting is more automated, manufacturers can produce more parts in a shorter amount of time.

Investment casting, on the other hand, is more cost-effective for low-volume production of less than 10,000 pieces. Die casting machines are more expensive and small batch runs cannot make up for the die casting cost. Investment casting requires less machinery, thus saving on tooling costs. Additionally, investment castings typically do not require secondary processing. Therefore, you can further save on processing costs.

Die casting or investment casting, which one is better for your needs?

Although die casting and investment casting are mature technologies, they are best suited for different applications. The casting method you choose will depend on your specific needs. For example, die casting is best suited for manufacturing high-volume parts quickly, affordably, and with good consistency. On the other hand, for smaller products with complex or intricate features, investment casting is preferred.

Die casting is also only suitable for non-ferrous metals such as aluminum, zinc, and copper. However, if you need to make parts from ferrous metals like stainless steel, Custom Lost Wax Casting will be your best choice. Often, your manufacturing requirements will determine the best process to choose. If you have any confusion about the selection process, please contact us.