Precision casting is a very complicated casting process. The castings are processed by annealing and solution treatment, mainly to improve the mechanical properties and obtain a stable size.

Annealing means that the aluminum alloy casting can be heated to a certain high temperature for a period of time, and then the process of cooling in the furnace is called annealing.

The annealing process can eliminate the internal stress of the casting, stabilize the size of the casting, and ensure that the casting does not deform. This will increase the plasticity of the casting. This process is a very important casting. Without this technique, castings cannot be improved very well and cannot be very effective.

What are the requirements for the performance of the shell in precision casting?

The basic function of the outer casing is to obtain a shiny and precise casting. The performance of the following types of shells must be as follows.

1. With good process performance, it can accurately replicate the shape of the investment and ensure accurate dimensions. Smooth face.

2. Have sufficient room temperature and high temperature strength and the necessary stiffness.

Precision casting processing tempering and normalizing

1 temper

The purpose of precision casting and processing tempering products is as follows:

1. Reduce brittleness, eliminate or reduce internal stress, and have great stress and brittleness after quenching of precision castings. For example, timely tempering will cause deformation or even cracking of castings.

2. Obtain the mechanical properties required for the workpiece. After the workpiece has undergone quenching hardness and high brittleness, in order to meet various performance requirements of various workpieces, the hardness can be adjusted by appropriate tempering to reduce the brittleness and obtain the required toughness and plasticity.

3. Workpiece size is stable

4. For some alloy steels that are difficult to soften by annealing, after quenching (or normalizing), high-temperature tempering is often used to make steel carbides suitable for aggregation, which will reduce the hardness and facilitate cutting.

2 frontal fire

The production of precision casting processing also needs to be standardized

Normalizing is to heat the casting to a critical temperature above 30-50 °C, suitable for holding time, and is called normalizing treatment during the cooling process of static air cooling. The main purpose of normalizing is to refine the structure of the structure, improve the performance of the steel, and obtain a near-balance mechanism.

The main difference compared to the annealing process is that the cooling rate is slightly faster and the heat treatment has a shorter production cycle. Therefore, annealing and normalizing can also meet the performance requirements of the parts, and try to choose the right source of ignition. Most medium and low carbon steel billets are generally used for heat treatment. Generally, alloy billets are often annealed. If normalizing, the cooling rate is faster, so that the fire after high hardness is not conducive to cutting.