Precision casting is a process in which a metal is smel […]
Precision casting is a process in which a metal is smelted into a liquid that meets certain requirements and poured into a mold, and cooled, solidified, and cleaned to obtain a casting having a predetermined shape, size, and performance. The casting blank is nearly shaped, and it is free of machining or a small amount of processing, which reduces the cost and reduces the time to some extent. Casting is one of the basic processes of the modern manufacturing industry.
Precision casting is a relatively economical method of forming blanks, which shows its economics for parts with complex shapes. Such as the cylinder block and cylinder head of the car engine, ship propellers and fine art. Some difficult-to-cut parts, such as nickel-base alloy parts for gas turbines, cannot be formed without casting.
In addition, the size and weight of the cast parts are wide, and the metal types are almost unlimited. The parts have general mechanical properties, and also have comprehensive properties such as wear resistance, corrosion resistance and shock absorption. Other metal forming methods such as forging , rolling, welding, punching, etc. can not be done. Therefore, the number of blank parts produced by the casting method in the machine manufacturing industry is still the largest in terms of quantity and tonnage.
There are many types of castings, which are customarily divided according to the modeling method:
1. Ordinary sand casting, including wet sand type, dry sand type and chemical hardening sand type.
2. Special casting, according to the modeling material, can be divided into special castings with natural mineral sandstone as the main modeling material (such as investment casting, clay casting, casting workshop shell casting, negative pressure casting, solid casting, ceramic type). Casting, etc. and special castings with metal as the main casting material (such as metal casting, pressure casting, continuous casting, low pressure casting, centrifugal casting, etc.) have different characteristics from other processes, mainly for wide adaptability. It requires more materials and equipment and pollutes the environment. Casting produces dust, harmful gases and noise that pollute the environment. It is more serious than other mechanical manufacturing processes and requires measures to control it.
With the increasing demands of modern society for energy conservation and the call for natural environmental protection, the trend of casting products is more inclined to the comprehensive performance of castings, higher precision, less margin and a smoother surface. New casting alloys will be developed, new equipment and new technologies will appear accordingly, precision casting will gradually enter people's attention, precision casting has more accurate shape and higher casting precision than the traditional foundry industry.