Casting is a process in which metal is smelted into a liquid that meets certain requirements and poured into a casting mold. After cooling, solidification and cleaning, a casting with a predetermined shape, size and performance is obtained. Because the casting blank is almost formed, it can achieve the purpose of avoiding machining or a small amount of processing, reducing the cost and reducing the time to a certain extent.

Casting is a relatively economical method of forming blanks, and it can show its economy more for parts with complex shapes. Such as the cylinder block and cylinder head of car engine, ship propeller and exquisite artwork. Some parts that are difficult to cut, such as nickel-based alloy parts of gas turbines, cannot be formed without casting.
In addition, the size and weight of the cast parts are suitable for a wide range, and the types of metals are almost unlimited; while the parts have general mechanical properties, they also have comprehensive properties such as wear resistance, corrosion resistance, and shock absorption. They are other metal forming methods such as forging. , Rolling, welding, punching, etc. Therefore, the number and tonnage of blank parts produced by casting methods in the machine manufacturing industry are still many.

There are many types of casting, which are divided into habitually according to the modeling method:

1. Ordinary sand casting, including 3 types of green sand, dry sand and chemically hardened sand.

2. Special casting, according to the modeling material, can be divided into special casting with natural mineral sand and gravel as the main modeling material (such as investment casting, clay casting, casting workshop shell casting, negative pressure casting, solid casting, ceramic mold Casting, etc.) and special casting with metal as the main mold material (such as metal mold casting, pressure casting, continuous casting, low pressure casting, centrifugal casting, etc.).

Casting production has different characteristics from other processes, mainly due to wide adaptability, many materials and equipment required, and environmental pollution. Casting production will produce dust, harmful gases and noise that will pollute the environment, which is more serious than other mechanical manufacturing processes, and measures need to be taken to control it.

With the increasing demands of modern society for energy saving and natural environment protection, the development trend of casting products is more towards the comprehensive performance of castings, higher precision, less margin and smoother surface, so New casting alloys will be developed, new equipment and new technologies will appear correspondingly, and precision casting will gradually come into people’s sight. Compared with the traditional casting industry, precision casting has more accurate shapes and higher casting accuracy.