Investment casting is one of the traditional methods of metal casting that produces parts with fine detail and an excellent surface finish. 3D metal printing, on the other hand, is becoming more and more popular commercially, and this technique allows for the rapid production of parts with complex, higher precision.
Previously we discussed CNC machining vs 3D printing, and which is the best method for prototyping. This time we’ll explore how investment casting differs from 3D metal printing to help you make a clearer decision when choosing a production method for your project.
What is investment casting?
Investment casting (also known as lost wax investment casting or precision investment casting) is a manufacturing process in which a ceramic, plaster or plastic shell is used on the outside of a wax mold, which is removed in a furnace, and then a metal liquid is poured into the shell to form the casting. Investment casting can produce internal or external features, thin walls and internal channels to achieve a near net shape.
Advantages of investment casting
-High dimensional accuracy and surface finish of parts
EK can manufacture products based on product drawings provided by the customer. Investment casting uses ceramic molds that produce a smoother surface finish, typically casting with an average surface finish of 125 RA. more accurate than other casting processes.
-Low cost, high economic efficiency
Investment casting requires less expensive equipment, and the near-net shape of the casting requires very little machining, thus minimizing material waste. Low energy, material consumption and mold costs. Very little initial investment in product development. Therefore manufacturing costs are very competitive. With Easiahome’s in-house mold manufacturing, the initial cost of investing in casting molds is typically lower than die casting and forgings.
-Tight tolerances, dimensions
Investment casting, also known as precision casting, can produce precision parts. Due to the nature of the process, the tolerances of investment casting are much tighter than those of 3D metal printing. Tolerances can be as tight as + – 0.1 mm, resulting in highly accurate castings. Investment casting can be used for both large and small castings. Complex micro parts of 1/10th of an ounce or less can be cast, as well as large parts weighing up to 50 pounds.
-Multiple Material Options
The raw material selection for investment casting is diverse and can be cast in a variety of alloys, including stainless steel, brass, bronze, cobalt, nickel, and custom alloys. Check out our castings.
However, due to the tedious nature of the investment casting process, the delivery time for the finished casting can take longer than for 3D metal printing, and it can take weeks or even months to get the desired part. Once a part has been machined, no changes can be made to it. For more information on precision casting, see our Precision Casting Solutions.
What is metal 3D printing?
3D printing technology, a machine that directs a high-precision laser to metal powder particles, melts the desired portion of the metal powder, solidifies it, and then makes metal parts. It enables difficult forming such as complex shapes and high-strength metals, and prints dense 3D shapes. The process generates little material waste and enables the construction of complex geometries that cannot be achieved by other manufacturing methods.
Advantages of metal 3D printing
-Small batch production
Compared to metal castings, 3D metal printing produces one-off parts in very small quantities at a fraction of the cost.
-Complex Geometries
Small, complex shapes that are difficult and/or costly to machine or process as metal castings. This will reduce or even eliminate the associated tooling costs.
-Delivery Time
3D metal printed parts are produced in fewer steps and are typically produced much faster than investment casting. Deliveries to customers can be made in as little as 10 days. Mid-production changes can be made at a much lower cost.
-Sample Testing
3D metal printing allows for direct mold-free production of injection molded inserts and cores, allowing for rapid prototyping for customer review.
-Recyclable Materials
The metal powders used in 3D printing are highly recyclable. Typically, less than 5% is wasted. After each print, the unused powder is collected, sieved, and then filled with fresh material to the level needed for the next print.
-Compatibility with high-strength materials
Materials such as nickel or cobalt-chromium high-temperature alloys are difficult to machine using traditional manufacturing methods. But by using metal 3D printing to create near-net shape parts, and then processing them, a very high surface finish can be achieved.
However, the cost of metal 3D printing is often much higher than investment casting, from the cost of the metal powder to the machine time. Parts can cost up to thousands of dollars. On the other hand 3D metal printing technology cannot produce metal parts in high volumes to meet customer expectations.
When to use investment casting
√ Requirements for cast surface finish are extremely high.
√ External molding and tight tolerances are required.
√ Parts have complex shapes or are asymmetrical and contain fine details.
√ The design contains multiple and/or complex internal channels.
√ Part sizes are typically small or medium-sized, typically less than 1,000 lbs/454 kg.
√ Produces more parts at a lower cost.
When to use 3D metal printing
√Shorter production times
√Greater design freedom to create geometrically complex castings
√Print complex multi-piece cores (e.g. pump impellers) as a single unit, eliminating the need to assemble individual components.
√Materials that are difficult to machine, such as metallic high-temperature alloys.
Summary
This article describes the differences between investment casting and 3D metal printing and details the advantages of investment casting vs 3D printing, and how to choose which part casting method to use in which situation.
To learn more about investment casting, contact an Easiahome representative.
𝘌𝘢𝘴𝘪𝘢𝘩𝘰𝘮𝘦 𝘰𝘧𝘧𝘦𝘳𝘴 𝘢 𝘸𝘪𝘥𝘦 𝘳𝘢𝘯𝘨𝘦 𝘰𝘧 𝘮𝘢𝘯𝘶𝘧𝘢𝘤𝘵𝘶𝘳𝘪𝘯𝘨 𝘤𝘢𝘱𝘢𝘣𝘪𝘭𝘪𝘵𝘪𝘦𝘴, 𝘪𝘯𝘤𝘭𝘶𝘥𝘪𝘯𝘨 𝘪𝘯𝘷𝘦𝘴𝘵𝘮𝘦𝘯𝘵 𝘤𝘢𝘴𝘵𝘪𝘯𝘨 𝘴𝘦𝘳𝘷𝘪𝘤𝘦𝘴, 𝘊𝘕𝘊 𝘮𝘢𝘤𝘩𝘪𝘯𝘪𝘯𝘨 𝘴𝘦𝘳𝘷𝘪𝘤𝘦𝘴, 𝘪𝘯𝘫𝘦𝘤𝘵𝘪𝘰𝘯 𝘮𝘰𝘭𝘥𝘪𝘯𝘨, 𝘢𝘯𝘥 𝘳𝘢𝘱𝘪𝘥 𝘱𝘳𝘰𝘵𝘰𝘵𝘺𝘱𝘪𝘯𝘨 𝘴𝘦𝘳𝘷𝘪𝘤𝘦𝘴 𝘧𝘰𝘳 𝘢𝘭𝘭 𝘺𝘰𝘶𝘳 𝘱𝘳𝘰𝘵𝘰𝘵𝘺𝘱𝘪𝘯𝘨 𝘢𝘯𝘥 𝘱𝘳𝘰𝘥𝘶𝘤𝘵𝘪𝘰𝘯 𝘯𝘦𝘦𝘥𝘴. 𝘗𝘭𝘦𝘢𝘴𝘦 𝘷𝘪𝘴𝘪𝘵 𝘰𝘶𝘳 𝘸𝘦𝘣𝘴𝘪𝘵𝘦 𝘧𝘰𝘳 𝘮𝘰𝘳𝘦 𝘪𝘯𝘧𝘰𝘳𝘮𝘢𝘵𝘪𝘰𝘯 𝘰𝘳 𝘵𝘰 𝘳𝘦𝘲𝘶𝘦𝘴𝘵 𝘢 𝘧𝘳𝘦𝘦, 𝘯𝘰-𝘰𝘣𝘭𝘪𝘨𝘢𝘵𝘪𝘰𝘯 𝘲𝘶𝘰𝘵𝘦.