Although investment casting, or lost wax casting, was first developed thousands of years ago, it is now viewed as the future for the production of high-strength and lightweight metal components. Often referred to as precision casting, the investment casting process is frequently used in many industries due to its keen ability to create parts with strict tolerance requirements, while requiring only minimal surface finishing or machining for completion.
The name investment casting is derived from the pattern being “invested” or surrounded with a refractory material. The technique employs a mold formed around a wax pattern, which eventually melts away, to create the finalized part, which can weigh anywhere from a few ounces to several hundred pounds.
There are many benefits associated with investment casting. The enhanced flexibility of being able to utilize nearly any metal material makes this process suitable for a variety of industries and applications, including aerospace, energy, automotive and more. There’s also a great deal of room for flexibility, as investment casting can be executed using many different alloys, including tool steel, stainless steel, carbon steel, aluminum and low-alloy steel.
In addition to producing parts of intricate shapes and sizes, investment casting helps minimize material waste and conserve energy. It also provides manufacturers the ability to cast complex parts with superb surface finishes, greater dimensional accuracy and no flash or parting lines.
We at Barron Industries understand the importance of saving on costs when and where possible. Fortunately, investment casting can reduce manufacturing production costs by as much as 40%. Additionally, it also requires less time and materials than other casting methods.
Investment casting, or precision casting, is a process through which a mold is created around a pattern that is then melted out of the mold and replaced with molten metal.
The steps for creation are contingent on several factors, including the alloy type and size of the part being created. As a leader in investment casting, Barron Industries couples our unparalleled knowledge and experience with state-of-the-art technology to determine the best course of action for your investment casting project. Here breakdown of the entire process:
Our lost-wax casting process is a seamless, productive and cost-effective way to produce high strength castings with greater dimensional accuracy, higher consistency, superior product integrity and improved surface finish.
The first step in investment casting is to develop the pattern. This is generally done by injecting wax into a metal tool or “die” to form a single piece. For rapid prototypes Barron uses our in-house additive manufacturing technology to 3D print patterns.
After the pattern is created, they are then connected to a central wax gating system, which includes the sprue, to form the tree assembly. Rather than create parts one at a time, the sprue works as a mounting surface to create several patterns into one mold. Those molds are later filled with an alloy. Additionally, the sprue creates a flow path for said alloy to flow into the various empty crevices of the wax pattern.
Once the wax pattern tree is assembled, it’s then dipped into a ceramic slurry and covered with coarse material. Barron’s six-axis dipping robot ensures consistency and uniformity of shell production in intricate and complex parts. When the slurry dries, it produces a ceramic shell around the wax tree. This process is repeated until the mold shell reaches its desired thickness and hardens completely.
After the shell is built, a flash fire oven is used to remove the wax prior to the metal being poured into the mold. The heat from the oven melts away the leftover wax and treats the shell so it’s ready to cast. Additionally, the scorching oven temperature provides additional benefits, like increasing the stability and overall strength of the ceramic cast.
Once the mold has been cleaned, it is then preheated to a specific temperature. This helps prevent the alloy from solidifying prior to being filled. Through induction melting, the alloy is melted into a ceramic crucible. A high-frequency electric current will then create a magnetic field surrounding the alloy which creates electric fields within the metal called “eddy currents.” Because of the material’s electrical resistance, these eddy currents have the ability to heat the alloy. When heated accordingly, the molten alloy is then poured into the mold cavity. The mold is then given time to cool.
After removing the parts from the sprue and taking out the gates, the surface of the part needs to be finished. This can be done in a variety of ways. At Barron Industries, we offer the following finishing services:
With nearly a century of experience, the experts at Barron Industries investment casting foundry specialize in melting and pouring over 200 different types of ferrous and non-ferrous alloys, including high-strength stainless steel, aluminum, armor and more. By following the necessary process controls and secondary thermal treatment parameters, our team is well equipped to meet any customer’s unique requirements.
Barron Industries can create both ferrous and non-ferrous precision castings ranging from 2 oz. to 150 lbs. We are AS9100 Certified and NADCAP accredited for our welding, digital radiography and dye penetrant testing. Barron’s turnkey manufacturing process includes the production of stainless steel castings, aluminum investment castings and more.
Prior to a part being created, we utilize Solidification Modeling software to gauge what a casting’s internal quality level will be. In doing this, we can drastically cut time and costs associated with traditional trial and error phases. In addition to helping you reduce weight, lead time and overall production parts, we will work with you to improve the overall quality and function of your finished part.
The team at Barron Industries has the capability to finish cast parts via machining, which is all executed in-house within our 15,000 square foot machine shop, including our newest addition, the Doosan DVF 5000 5-axis vertical machining center. We utilize state-of-the-art CNC equipment from trusted brands like Makino, Mori Seiki and Mazak, including 5 horizontal, 5 vertical milling and 3 lathes combined with grinding, brazing, welding, assembly and fabrication.
The knowledge and expertise of our team speak for themselves. Our technicians are dedicated to providing our customers with top-of-the-line service, which is why we’re always searching for new ideas to further advance our casting procedures. To perfect our lost-wax casting method, we’ve implemented the following components to streamline the process.
State of the Art Robotic Technology: Barron Industries utilizes robot arms to better ensure consistency in shell dipping, coating and formation. The deployment of technology results in greater consistency and higher quality castings for our customers.
Optimal Furnace Capacity: To ensure that we complete any and all casting projects within the predetermined time frame, our facility boasts three steel and two aluminum melting units, as well as two ovens for wax burnout from the ceramic mold and four ovens for preheating the shells.
Ceramic Shelling: Barron Industries is an industry leader in investment casting services. We were one of the first companies to utilize ceramic shelling core technology. In implementing this, our research and development team was able to reduce manufacturing costs by 20%.
Manufacturing Enterprise Resource Planning Software: This unique software utilizes operational intelligence to provide advancements in the investment casting process, including accountability, quality and transparency.