Metal has played a critical role in construction, defense, and art for thousands of years of human history. Metalworking and casting are traditional ways to produce metal parts and components with precision. The investment casting process allows manufacturers to produce accurate parts and components using molds.
It is a popular option for manufacturers due to investment casting benefits like accuracy, cost, and lower waste. More industries are starting to use this casting method to meet client demand. Learning the steps in investment casting can give your company an advantage.
Discovering and implementing the casting process tips is the best path forward for your brand. Continue reading to learn more about each step of the process for precision casts today!
What Is Investment Casting?
Investment casting is a popular casting process with a history dating back hundreds of years. The word “Investment” is used to define it because the mold you use is invested by a liquid refractory material.
Other options include combining wax and mud to create a more durable mold. The wax remains inside, with the mud providing an outer layer. Upon making the cast, you can place it in hot water to melt the wax while keeping the mud and metal intact.
What Is the Investment Casting Process?
You’ll need to know several steps when you begin the investment casting process. Incorrect steps can result in a less-than-stellar result for your first casting attempt. From creating an investment pattern to making the individual casting, here are the eight steps to complete the casting process.
1. Create the Investment Casting Pattern
The wax pattern is integral when gathering the investment casting materials for your next contract. It’s the first step toward creating precision metal parts and making your clients happy.
It is a more cost-effective way to make precision metal parts while minimizing waste. You can begin by injecting wax into a metal mold to make your first pattern.
2. Make a Wax Tree
One of the many advantages of investment casting is reducing waste, but it’s also effective for efficient production methods. Upon completing your wax pattern, you can begin making a wax tree to enter mass production of the metal part or component.
Making small parts one at a time is time-consuming and expensive. The wax tree allows you to create several precision metal parts in one attempt.
The best material to use is a wax sprue. The sprue allows your company to use several wax patterns at once. The gates on the sprue control the path of the molten metal you’re using for your casting.
3. Start Shell Building
Your tree is vital to begin building a shell for your molten metal. The ceramic shell will go around the tree at the beginning before surrounding the metal itself to provide a precision part.
The two primary steps to creating a shell for the investment casting process:
- Slurry coating
- Stucco coating
Slurry coating involves dipping the wax tree into a ceramic bath, also called a slurry. After creating the slurry coating, you’ll want to add sand or stucco to the wet surface.
Wait for your mold to dry, then repeat the process until the shell can withstand the stress of the investment casting process. You can move forward with the next step when the shell dries.
4. Remove the Wax
Finding effective ways to remove the wax is critical to producing quality, precision parts for your clients. The two most effective and popular methods are the steam de-wax and the flashfire oven.
The steam de-wax is the best option if you’re focused on reducing waste. The machine will remove most of the wax and allow you to reuse the leftovers.
The flashfire oven is effective because it burns off the wax. You can combine this method with steam de-wax to remove all pieces of wax for a clean shell or mold. Most manufacturers use both methods in conjunction with one another for the most effective molds.
5. Metal Pouring
Metal pouring can commence after you remove the wax from your investment casting mold. Preheating the shell or mold you’re using is best to prevent freezing or solidification when pouring the metal into the mold.
You want the shell to maintain a consistent material until you pour the molten metal into it. Combine the shell with the induction process to heat the metal alloy until it becomes molten. After the metal reaches its melting point, pour it into the shell.
6. Knock the Shell Off
When the metal pouring process is complete, removing the shell is vital to enjoy the investment casting benefits. You can use three mechanical methods to remove the shell from the metal part without causing any damage, which include:
- Hammer
- Vibratory table
- High-pressure water blast
You can combine all of these methods to ensure the ceramic shell is removed before accessing the completed metal part. Chemical removal of the ceramic shell is also possible, though it has drawbacks. The primary disadvantages are adverse health effects and harm to the environment.
7. Cut From the Tree
When you’re ready to collect and package the finished piece, remove it from the wax tree or cut it off. There are several methods for cutting the part from the tree.
Many manufacturers choose to use a chop saw, laser, or torch. The laser is effective but has limited applications for most foundry functions.
8. Start Individual Casting
After completing the investment casting process, you can progress toward individual casting. Finishing the casting can help you prepare to package it and send it to customers and clients.
Belting and hand grinding are two of the most effective methods. You can also polish the finished metal pieces before selling them to enhance their appearance.
What Are the Applications for Investment Casting?
Several industries rely on parts created with the investment casting process. Your manufacturing company can meet demand within these industries to become more sustainable and prosperous.
Power generation, firearms, gas and oil, food, and energy are some of the top industries that rely on casting process tips. Any industry that uses metal parts is an excellent candidate for enjoying the advantages of investment casting. You can learn when to use precision casting to create the parts clients depend upon.
Investment Casting Benefits
Learning the benefits of investment casting is essential if you’re considering adding it to your list of services offered to clients. The investment casting process can lower waste and costs while ensuring you provide your clients with the quality parts they need.
Take a look at the top benefits of using the investment casting process.
1. Surface Finish
One of the most apparent benefits of using the investment casting method is the improved surface finish compared to other methods. When you use a smooth wax pattern to create your ceramic shell, you ensure a smooth surface for the metal part.
Create your shell using an optimal ceramic layer to improve the surface finish. When you remove the wax and ceramic shell, the metal part or component will have a smooth and impressive finish.
2. Complex Geometries
The wax pattern you create is the final step before making your design using molten metal. The investment casting process allows you to create custom shapes and complex parts.
Pour the molten metal you’ve chosen into the shell and wait for it to cool. Upon removing the part from the shell, you’ll see the intricate design produced by your wax pattern and ceramic coating.
3. Versatile Alloys
Finding the best alloys for parts when working with clients is essential to retain the patronage of your manufacturing company. The ceramic shell you create with the casting process tips is rugged and durable.
The shells can withstand the extreme temperatures caused by poured molten metal. The alloy’s melting point is lower than that of the ceramic shell you’re using. Work with your clients to determine the parts they need and choose the best alloy to pair with the project.
4. Fine Details
Precision is one of the top advantages of investment casting for your manufacturing plant. When you coat the wax with liquid ceramic, the ceramic will adopt the fine details you’ve added to the pattern.
When you pour the molten metal into the shell you’ve created, the fine details will be transferred to it. After removing the shell from the metal, you’ll be able to see the fine details in the finished product. It is an excellent way to please customers and earn more business in the future.
Implement the Investment Casting Process at Your Company
Several industries rely on the investment casting process for precision metal parts and components. Learning about the investment casting process is vital to expanding your operations and making clients happy.
You’ll need to create a wax pattern before coating it in liquid ceramic. When the ceramic dries, you can pour the molten metal into it to create metal parts with various alloys. It’s the ideal way to serve clients in the firearm, gas, oil, food, and power generation industries.
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