Investment Casting Technology
Investment casting is a type of casting that offers higher dimensional precision and more design freedom compared to traditional casting methods. In investment casting production, paraffin-based wax is used as the model. In the investment casting process, the desired parts’ wax models are injected into a metal mold using an injection machine for each order quantity. The shape that emerges after the injected wax cools down is an exact replica of the metal part to be produced.
Advantages of Investment Casting Process
Good raw material is essential to purify the liquid metal to its purest form. Gas voids in metal casting result from the entrapment of gases like hydrogen, oxygen, and nitrogen during melting. To prevent this, it is necessary to minimize the hydrogen, oxygen, and nitrogen levels during the melting of the metal. Investment casting, a method that allows the production of complexly shaped parts in one piece, is advantageous due to its ability to shape metal. It has many advantages over other casting methods, including the ability to produce both very small parts starting from 1 gram and large parts. The investment casting process also allows for the production of complex parts that cannot be produced by many other methods.
Stages of the Investment Casting Process
The first step in the investment casting process is the modeling of the product to be produced. Modeling allows for the prototyping of the product. This process ensures the creation of the final product with flawless and millimetric precision. The produced wax models are attached to the runner part and the main wax body. The structure formed resembles a tree. Thus, gathering multiple wax models and producing multiple parts in a single casting process is beneficial. These wax models, standing together like a tree, are coated with several ceramic-based materials with refractory properties. The key here is to ensure the refractory coating has no cracks and is thick enough to withstand casting pressure and temperature. This process usually takes about 4-7 days. After the entire surface is coated and the drying process is completed, the wax material forming the main body and parts is removed through a special autoclave process with sudden pressurized steam. This leaves the interior of the refractory material hollow. This hollow space equates to the cavity of the body and parts to be cast. This space is referred to as the ceramic mold of the process, and ultimately the metal is melted and poured into this cavity.
Final Stage of the Investment Casting Process
The melted metal, prepared in the desired analysis, is poured into ceramic molds through a special process and left to cool. Once the cooling process is complete, the ceramic shell on the metal is removed using a vibration method, and the tree-like structure initially formed in wax becomes metal. The parts are then cut from this tree-like structure, sanded, blasted, and prepared for delivery as requested by the customer. This process allows for the casting of stainless steel, carbon steel, aluminum, magnesium, and their derivatives in the same method with various applications within the process.
Why Choose Investment Casting?
The advantages of investment casting are as follows;
- Reduction in Machining Cost
- Surface Quality
- Design Freedom
- Cost Savings
- Variety in Alloy Metal
- Low and Long-Lasting Mold Cost
- High Quantity Production in a Short Time