All About Investment Casting: Process, Benefits & Applications

One of the broadest casting techniques utilized in investment casting manufacturers in India. Engineers favor it because it has many advantages, including excellent dimensional precision, a smooth surface finish, complicated designs, quick production, and more.

We’ll quickly touch on its background before delving into its procedure step-by-step, applications, material capabilities, and pros and disadvantages.

What’s the Process of Investment Casting?

Engineers have developed a step-by-step process for investment casting manufacturers in India that produces the best casts over the years. This section outlines the six steps of the process.

• Establish the master pattern

The geometry of the finished part is reflected in the wax pattern. A “master pattern” benchmark can be used repeatedly for casting. Wax, wood, metal, silicone rubber, and other common materials make the master pattern dies. 

• Making of the wax pattern

The next step is assembling the several designs created in the previous stage into a single investment casting mold. Due to the merged pattern, it is referred to as a “tree.”

The patterns are then put together by operators using a sprue network. This gating system offers a seamless path for the metal to flow to all areas of the mold.

• Put Refractory Materials to Use (Dipping)

Operators then coat the pattern with refractory materials to give it the necessary qualities. Multiple dipping cycles are used during the coating process. 

They rotate the tree slowly and repeatedly into a bath of ceramic slurry and sand stucco. The ceramic shell encloses the wax pattern and gets thicker with each dipping cycle. The primary core, or first layer, significantly impacts the component quality and shape, so it is crucial to apply it carefully.

• Dewaxing

Melting removes the wax from inside the ceramic shell during the dewaxing procedure.

The mold will be positioned so that molten wax can easily flow out by operators. Most of the wax pours out of the mold when the steam in an autoclave heats it for up to 12 hours at 90° to 175°C. After that, bake the mold for a few hours at higher temperatures, up to 1000oC, to burn off any leftover wax and evaporate any moisture.

• Casting and Preheating

The actual investment casting manufacturers in India procedure are carried out at this step. To lessen the mold’s thermal shock when it comes into touch with hot liquid metal, operators pre-heat it.

To reduce casting faults brought on by turbulence, it is critical to maintaining the pouring rate at this moment. Furthermore, creating a vacuum environment surrounding the mold is advised if the molten metal tends to react with air. After pouring the metal, it solidifies and cools down inside the mold.

Post-Processing

In this stage, operators knock off the mold by impact using a hammer or water blasting. The part goes through numerous semi-finishing processes once it comes out of the mold.

Since the gating system is not a product component, these procedures also include turning it off. Similarly, flaws such as rough surfaces, sharp edges, and others are eliminated through grinding or blasting.

After post-processing activities, the part undergoes quality inspection. The inspection team performs tests, including die-penetrant testing, to check the component for flaws like fractures and porosity. 

Benefits of Investment Casting 

• Compatible with Complex Geometry: It can cope with complex geometries such as internal features, sharp curves, thin walls, and shallow tunnels.
• Fine Surface Finish: This casting technique may produce surfaces with finishes as fine as 3 microns. This is on par with or superior to other well-liked techniques like sand casting.
• Large Parts: This technique can handle a range of part sizes. It can handle components that are 100g in weight and a ton in weight.
• Excellent Dimensional Accuracy: The casting process uses a near-net form with minimal finishing tolerances.
• Wide Material Selection: This method is adaptable and works with various materials.

Investing Casting Applications

Numerous businesses utilize investment casting in a variety of ways. Below, list a few of them.

• Energy: This manufacturing process has a specialized application in the energy sector. 
• Marine: The marine industry frequently uses investment casting to create metal components. 
• Aerospace: Due to complex geometries and strength demands, this technology may make essential parts in aircraft engines and bodies.
• Medical: This process has an advantage in the medical business due to its capacity to cast small pieces with superior surface polish. 
• Automobile: Drive train components, rocker arms, and power train components are high-performance parts produced in the automotive sector.

Conclusion

Investment casting manufacturers in India is undoubtedly a highly technical procedure that needs expertise and knowledge to be carried out correctly.