Different Processing Methods of Precision Casting II


2. Investment casting: Investment casting uses a disposable wax pattern for each cast part. The wax is either injected directly into the mold or pre-coated with a liquid refractory material before injection. Molten forming material is then poured into the mold and allowed to harden and set into the shape of the wax pattern. The component is then ejected, while the wax pattern is melted out of the casting and made available for reuse.

Investment casting is often used to manufacture parts for the aerospace and automotive industries, as well as the military. Some of the central advantages of using an investment casting process include a high degree of accuracy and precise dimensional results, the ability to create thin-walled parts with complex geometries, the capacity for casting both ferrous and non-ferrous materials, and relatively high-quality surface finish and detail in final components.

Although it is highly precise, investment casting is usually more expensive than other comparable casting techniques, and is typically only cost-efficient when sand or plaster castings cannot be used. However, the expense can sometimes be compensated for with reduced machining and tooling costs due to investment castings’ quality surface results.

3. Plaster casting: Plaster casting is similar to the sand casting process, but using a mixture of gypsum, strengthening compound, and water in place of the sand. The plaster pattern is typically coated with an anti-adhesive compound to prevent it from becoming stuck against the mold, and the plaster is capable of filling in any gaps around the mold. Once the plaster material has been used to cast a part, it usually cracks or forms defects, requiring it to be replaced with fresh material.

The advantages offered by plaster casting include a very smooth surface finish, the ability to cast complex shapes with thin walls, the capacity for forming large parts with less expense than other processes, such as investment casting, and a higher degree of dimensional accuracy than that of sand casting.

This process tends to be more expensive than most sand casting operations, and may require frequent replacements of plaster molding material. It is usually more effective and cost-efficient when the quality of the surface finish is an important requirement.

4. Die casting: Die casting is a method of molding materials under high pressure and usually involves non-ferrous metals and alloys, such as zinc, tin, copper, and aluminum. The mold is coated with lubricant to help regulate the die’s temperature and to assist with component ejection. Molten metal is then injected into the die under high pressure, which remains continuous until the workpiece solidifies. This pressurized insertion is rapid, preventing any segment of the material from hardening before being cast. After the process is completed, the component is taken out of the die and any scrap material is removed.

A few of the major advantages provided by die casting include close size and shape tolerances, high component dimensional consistency and uniform design, and a reduced need for post-casting machining.

Despite its advantages, xinke-casting.com die casting has relatively high tool costs, making it more cost-efficient in high-volume product runs. It can also be difficult to ensure the mechanical properties of a die cast component, meaning these products usually do not function as structural parts.