Investment casting, known as the “paradigm of precision casting,” is an advanced near-net-shape forming process. It involves creating wax patterns or other low-melting-point materials to form investment molds, which are then coated with multiple layers of refractory material. After hardening, drying, and curing, the mold material is melted by heating, forming a hollow shell. Subsequently, through high-temperature sintering, molten metal is poured, and after cleaning, the final casting is obtained. These castings often closely resemble the final shape and dimensions of the part, sometimes requiring minimal machining or even direct use to meet specifications.

  • Detailed Process Flow

Investment casting consists of some key steps: wax pattern formation, tree assembly, shell making, wax removal and baking, melting and pouring, and final casting production.

1，Wax mold forming. This is the first critical step in investment casting. It involves injecting molten wax into a pre-prepared mold cavity. Once the wax cools, it is removed from the mold to obtain the desired wax pattern. This step lays the foundation for subsequent processe

2，Tree assembly. The group tree is formed by welding multiple wax patterns to the gating system, preparing them for subsequent processing steps. During the shell-making process, a pre-prepared silica sol coating is first applied to the surface of the wax mold, followed by the sprinkling of refractory sand. After drying and hardening under specific temperature and humidity conditions, a dense refractory layer forms on the wax mold surface. This step must be repeated 5-6 times to ultimately construct a silica sol shell with sufficient strength and refractory properties.

3, De-gassing and Baking: De-gassing involves melting and removing the wax from the shell at high temperatures to ensure the quality of the mold. Subsequently, baking is typically performed to further eliminate residual wax and moisture from the mold shell.

4，Melting and pouring. During these 2 processes, precise batching must be performed according to the material requirements of the product. Subsequently, the molten steel undergoes smelting, slag removal, and spectral testing to ensure compliance with the required composition. The pouring is then conducted under ideal conditions.

5，Finally, in the stage of obtaining the finished casting, after cooling and shell removal, the complete finished casting is obtained and can undergo further processing.