The core process of Investment casting encompasses every critical step, from the preparation of raw materials to the final formation of precision castings. These steps are interconnected and interact with each other, collectively ensuring the high quality and precision of precision casting products.
Mold and Wax Pattern Preparation
Digital design acts as the starting point for mold and wax pattern preparation, employing advanced CAD technology. Engineers precisely construct three-dimensional models of the molds. Subsequently, these models are transformed into physical molds through high-precision machining equipment, ensuring that their dimensions and shapes match the design exactly. After the mold machining is completed, the wax pattern forming process begins. Here, the molten wax material is injected into the mold, and upon cooling, a wax pattern consistent with the final casting is obtained.
Shell Building
The process of creating a shell mold is intricate. Initially, a layer of slurry is applied to the wax model's surface, followed by the sprinkling of refractory materials such as zircon sand or mullite-based materials, and then the drying process. This sequence must be repeated multiple times to form a robust shell with sufficient thickness, ensuring it can endure high temperatures and the impact of molten metal during the casting process.
Melting and Casting
Melting and casting are critical steps in the formation of castings. Initially, the wax model is removed through heating, leaving behind the cavity of the mold shell. Subsequently, the mold shell undergoes sintering treatment to enhance its high-temperature resistance. Next, the metal is melted to an appropriate temperature and poured into the cavity of the mold shell using vacuum casting technology. After cooling and solidification, the metal casting that meets the requirements is obtained.
Post-Processing
The post-processing stage encompasses several steps, including shakeout, cutting, finishing, and inspection. Shakeout serves to remove the mold shell, cutting separates the casting from the gating system, finishing enhances the dimensional accuracy and surface finish of the casting, and inspection ensures that the casting meets the design specifications and quality standards.
