Investment casting: The model of precision casting technology

Investment casting, also known as precision casting, is a metal forming technology with a long history and is widely used in industrial fields. With its high precision, high complexity and high surface finish, it is the preferred method for manufacturing complex parts.

The core principle of investment casting is to make a model of a part from a fusible material (usually wax or plastic), and then coat the model with multiple layers of refractory material to form a fire-resistant shell. After the refractory has hardened, the model material is melted and drained, leaving a cavity with the same shape as the original model. Then, the molten metal is poured into this cavity, and after the metal has cooled and solidified, the refractory shell is broken and the metal casting is removed. In this way, metal parts with complex shapes and fine details can be made.

The process of investment casting can be divided into the following steps:

1. Model making: First, wax mold or plastic mold is made according to the design drawing of the parts. These models are usually composed of multiple parts to facilitate subsequent assembly and demoulding.

2. Coated with refractory material: Immerse the model in refractory paste, then sprinkle with refractory sand, repeat many times until a certain thickness of refractory shell is formed.

3. Model melting: The model coated with refractory material is heated so that the wax or plastic inside melts out, leaving a precise cavity.

4. Pouring metal: Molten metal is poured into the cavity, and the metal fills every detail of the cavity during the cooling process.

5. Hulling and cleaning: After the metal solidifies, break the refractory shell, remove the casting, and carry out subsequent cleaning and polishing work.

6. Heat treatment and processing: Heat treatment and further machining of castings are carried out as required to achieve the required dimensional accuracy and surface quality.

Because of its unique advantages, investment casting is widely used in many fields:

· Aerospace: Used in the manufacture of engine parts, turbine blades and other parts requiring high precision and high strength.

· Medical instruments: For the production of surgical instruments, dental implants and other products requiring high precision and biocompatibility.

· Jewelry manufacturing: Investment casting plays an important role in the jewelry industry because of its ability to produce complex and elaborate ornaments.

· Automotive industry: used to manufacture engine cylinder blocks, valves and other key components to improve vehicle performance and safety.

Investment casting technology, with its ability to produce complex shapes and high-precision parts, has become an integral part of modern precision manufacturing. With the continuous advancement of materials science and manufacturing technology, investment casting will continue to play its unique role in the industrial field, driving product innovation and the development of manufacturing.