Precision Casting Technology
Precision casting is a casting type that has higher dimensional accuracy and freedom of part design in its manufacture compared to traditional casting methods. Paraffin-based wax is used as a model in investment casting. In the investment casting process, the wax models of the desired parts are injected into the metal mold by the injection machine. The shape that comes out after this injected wax cools down is exactly the same as the metal part to be produced.
Advantages of Investment Casting Process
It is necessary to use good raw materials in order to make the liquid state of the metal the purest. Gas gaps that occur in metal casting are caused by the trapping of the gases generated during melting in the metal. In order to prevent this situation, the hydrogen, oxygen and nitrogen ratios should be minimized during the melting of the metal. Precision casting, a method that enables the production of multi-shaped parts in one piece, is advantageous in that it can shape metal. Other casting methods have many advantages over manufacturing methods. The most important of these is the ability to produce very small parts, starting from 1 Gr. And large parts by casting method. It is also possible to produce complex parts that cannot be produced by many methods with the investment casting process.
Stages of the Investment Casting Process
In the investment casting process, the product to be produced is modeled first. The prototype of the product to be produced can be obtained by modeling. With this process, it is ensured that the main product is formed smoothly and in millimetric dimensions. The wax models produced are attached to the runner part and the main wax body. The structure formed in terms of shape resembles a tree. Therefore, it is useful for combining multiple wax patterns and producing multiple parts in a one-time casting process. These wax models in the shape of a tree are covered with a few ceramic-based materials resistant to high temperatures with refractory properties. The issue to be considered here is that the coated refractory does not have any cracks and is thick enough to withstand casting pressure and temperature, this process takes approximately 4-7 days. After the entire surface is covered and after the drying process is completed, the wax material forming the main body and the parts is subjected to a special autoclave process that generates sudden pressurized steam and the wax inside the ceramic shell is removed. Thus, the refractory material remains hollow. This gap is equal to the space of the body to be cast and the parts connected to it. This cavity formed is qualified as the ceramic mold of the process and as a result the metal is melted and poured into this cavity.
Final Stage of the Investment Casting Process
The molten metal prepared in the desired analysis is poured into the ceramic molds with a special process and left to cool. After the cooling process is completed, the ceramic shell on the metal is removed by vibration method and the tree-shaped structure, which is formed as a candle, becomes metal. The parts are then cut from this tree-shaped structure, sanded, sandblasted and prepared for delivery as requested by the customer. With this process, stainless steel, carbon steel, aluminum, magnesium and their derivatives can be cast with the same method with different applications in the process.