Metal prototype casting is a process used to make prototypes of metal parts. Metal prototype casting is a process in which liquid metal is poured into a specific casting cavity, and after it cools and solidifies, a metal prototype with the same shape as the cavity is obtained. It can quickly and accurately transform design concepts into actual metal models, providing an effective solution for product design verification, performance testing and small-batch production. Here is a detailed introduction to it:
How the prototype casting process works
SLS prototype creation
The first step in the prototype casting process is to build an SLS prototype directly from the CAD file. This process takes only a few hours to complete without the need for a mold.
No mold required
Then, we will coat the model with wax to prepare it for production. After that, we will use conventional processes to create a part that meets production quality standards.
Wax pattern assembly
For ease of pouring, the mold is "wax welded" on the center gate or gate group. Many molds are fixed on the gate to improve efficiency.
Shell making
The assembled gate is then immersed in ceramic slurry. After draining, the sprue is coated with a layer of fine silica sand or plaster sand. This process is repeated several times, using progressively coarser ceramic materials, to achieve sufficient "shell" strength.
Dewaxing
The shelled sprue is then rapidly heated in a furnace or autoclave to dewax, leaving a perfectly wax-free cavity.
Preheating the Shell
The shell is then fired at temperatures between 1600° and 2000°. This solidifies the inside of the shell into a smooth, hard and strong ceramic material.
Pouring
The sprue is then removed from the furnace and molten metal is poured into it. Once the metal has been filled into the shell, it needs to be cooled and the shell material removed from the outside of the casting.
Finishing the Part
After the ceramic shell has been removed, the casting is cut from the sprue and then goes through a series of finishing operations. These operations include various cleaning stages, grinding, electroplating, machining and heat treatment.
Advantages and limitations
Advantages:
It is possible to produce metal parts prototypes with complex shapes and precise dimensions to meet various design requirements; a variety of metal materials can be selected for casting to meet different performance requirements; compared with other processing methods, the casting process has higher efficiency and lower cost in mass production.
Limitations:
Some defects may occur during the casting process, such as pores, sand holes, shrinkage, etc., which need to be avoided and eliminated through strict process control and quality inspection; for some parts with high precision and high surface quality requirements, a lot of machining may be required after casting to meet the requirements; the casting process has a certain impact on the environment, such as dust, noise and exhaust gas, etc., and corresponding environmental protection measures need to be taken.