Lost wax Casting

What is lost wax casting?

Lost wax casting, also known as "investment casting", "precision casting"is the process by which a single metal object is cast from a wax model. It is a highly versatile process that achieves exceptionally detailed results. This guide will cover how to start lost wax casting and what you can create with the process.
Lost wax casting builds a mold around a sacrificial wax model. After the mold investment is set, the wax is melted out and forms a cavity where the metal or glass flows in. Using this method of casting captures fine details in both metal and glass. This ancient method has been used since 3000 B.C. to visually capture the stories of ancient cultures and religions throughout history.

What is the lost wax process used for?
Lost wax casting is a 6,000-year-old process still used in both manufacturing and fine art. The precision and accuracy of the process have made it an ideal method for producing objects with thin walls, intricate details, and close tolerances. The process is used to create parts for transportation, agricultural, and medical industries, to name just a few. It can be used to create objects from simple to complex in various metals by casting an original wax model or pattern. The wax model makes an expendable mold that can only be used once in casting. This guide focuses on the lost wax casting process with metallic alloys. You can also use lost wax casting techniques to create cast glass objects.
Huawei Casting has the experience, facilities, and capabilities for all of your lost wax casting and lost wax casting products needs. Also known as  investment casting, lost wax casting is a multi-step type of metal casting and Trident's cost-effective tooling program makes lost wax casting an  economical process to deliver an accurately-cast product. Although lost wax casting is an ancient metal casting method, Huawei Casting  uses the latest  technologies to meet your custom lost wax metal casting needs at competitive prices.

Lost wax casting process in 8 steps
The basic lost wax casting process involves creating a pattern and a mold, then pouring molten metal into the mold. You will then extract the solid metal casting and finish your piece. This process is customizable for different types of metal casting, along with shapes, sizes, and more. The description below is based on smaller-scale casting processes, often used for jewelry. While essentially the same, in larger castings the mold material is made of Ceramic Shell (colloidal silica and various grades of silica), rather than plaster.
1.Create a model in wax
Create your desired design in wax before building a mold around it. This wax model can only be used once. After that, shape it with texturing tools, a soldering iron, and a heat gun. Many experienced wax sculptors swear by repurposing dental tools to sculpt and carve unique designs in wax effectively. Hollow out your wax model if possible.
When shaping your pattern, make sure you account for any anticipated shrinkage when the metal cools. Patterns may also be gated with sprues to allow the molten metal to flow into the mold. This is especially important if your design contains small intricate elements that may not fill with metal during the casting process.
2.Make your mold
You can make a mold using a combination of plaster and silica. Use a gram scale to measure each ingredient and mix equal parts by weight of plaster, silica, and water until the investment has the consistency of heavy cream. Plaster gives the mold support and silica has a high refractory, so it can withstand a lot of heat.
When working with dry materials, make sure that your work area is well ventilated, and wear a respirator when working with dry investment.
3.Remove the wax
The easiest way to melt the wax out of a small mold is in a microwave. First, remove any metal clamps you might have added to your mold, then prop it up on clay supports over a small container underneath to collect the wax. Heat in short bursts in the microwave until all of the wax has dripped into the small container. You can also burn out the wax in a kiln.
4.Choose the metallic alloy
All metal castings are produced from either ferrous or non-ferrous alloys. Alloys are a mixture of elements that provide the best mechanical properties for the final cast’s use. Ferrous alloys include steel, malleable iron, and gray iron. Non-ferrous alloys most commonly used in casting are aluminum, bronze, and copper. If you are working with precious metals in a jewelry studio, you may work with silver, copper, gold, and platinum. Less common, but especially spectacular, are metal castings with iron, which casts molten iron into a ceramic shell or resin-bonded sand mold.
5.Melt the alloy
Melting processes vary between alloys because each alloy will have a different melting temperature. Essentially, melting consists of placing the solid alloy in a crucible and heating it over an open flame for smaller projects or inside of a furnace for larger amounts.
6.Pour into the mold
Pour the molten metal into the mold cavity. If it is a small casting, you may simply pour from the crucible where the metal was heated directly into the mold. However, a larger casting may require a small team to support heating the metal inside a furnace and transferring the metal into a larger crucible or ladle before being poured into the mold.
Make sure to follow all recommended safety guidance when pouring molten metal. Wear protective clothing, including natural fiber clothing, long pants and sleeves, insulated gloves, and safety goggles. Work in a well-ventilated space to avoid any risks from dangerous fumes. Ensure you have a chemical fire extinguisher nearby and keep your walkway between the furnace and the mold clear. Allow the mold to solidify before moving on to the next step.
7.Release the cast from the mold
When the metal has cooled and solidified, you can remove it from the mold. You will want to quench the plaster in water after the metal has solidified. The water will help break away the mold. If you cast it into a ceramic shell, you can break the mold and chip it away using the necessary equipment.
8.Finish your piece
File and polish your solid metal cast! Finishing techniques include scrubbing away excess mold material in water, breaking off the casting gates with clippers for small objects, or even an angle grinder for large pieces. You can also choose to polish or patina your metalwork to give it color and dimension.

Advantages of Lost Wax Casting

This method is ideal for crafting small, complex geometric shapes that have intricate features with one mold.

Lost Wax Casting is highly versatile. Because you can combine multiple wax patterns to create one unique mold, you can configure parts you could not make with a machine or tools, making it a worthwhile alternative to weldments.

Dimensional precision and smooth finishes are other benefits of this casting method. The casters form the ceramic shell around even patterns, leaving behind no parting line because only one mold makes the casting, not two. The result is a smooth finish averaging around a 125 micro finish, but post-process smoothing can achieve a more refined finish, if necessary.

Other advantages of Lost Wax Casting

Reusable Materials: Design engineers can reuse the melted wax for another pattern. They can also reuse the mold, thanks to its strength.
Tight Tolerances: Investment casting can have a tolerance of .003″, which is tighter than most casting processes such as die casting.
Design Capabilities: With investment casting, design engineers can incorporate identifying markers to the casting, such as numbers, logos, and product IDs.

Disadvantages of Lost Wax Casting

Despite the beneficial nature of lost-wax casting, it does have its drawbacks. The most significant disadvantage is the size limitation. Because so few design engineers can produce large parts using this technique, it may not be the best option for a client who needs to fabricate a bulky component.

This process is best for casting small intricate components. Parts exceeding 75 pounds are better suited for other casting methods.

Lost Wax Casting shells also have limitations on their size and depth. They cannot be smaller than 1.6mm or deeper than 1.5 times the diameter. If your casting design requires cores and cannot fit these requirements, you may need to seek another process.

This technique is more complicated than other casting processes, and it requires a substantial amount of preparation and specialized equipment. As a result, the upfront cost of investment casting can be more expensive than sand casting or die casting, but the production cost per unit decreases with larger orders.

Our lost wax casting services:
•avoid elaborate tooling for parts with unusual or complex internal configurations
•efficiently and accurately produce small, intricate, or hard-to-machine shapes
•create higher quality, more detail, and greater consistency for many parts
•efficiently combine several machined parts into one casting
•are ideally suited for both long and short runs
•have the ability to cast metals and alloys that are hard to machine or fabricate
•are able to make parts that cannot be produced by normal manufacturing techniques
•produce virtually identical finished parts
•require minimal surface finishing and only minor machining

Lost Wax Cast Materials
•Steel
•Aluminum
•Stainless Steel
•Brass
•Bronze
•Copper

Our company is one of the most professional Lost wax Casting manufacturers and suppliers in China, and our investment casting foundry with powerful machining capabilities. Be free to buy bulk Lost wax Casting from our factory. All lost wax investment casting products and machined parts are with high quality.