What is pressure casting?
2. high efficiency machine high productivity, such as domestic J III 3 type horizontal cold air machine an average of eight hours can be 600 ~ 700 times of die casting small, hot chamber die casting machine every eight hours can be 3000~7000 times of die casting; long life, a pair of pressing mould, die casting bell alloy, life of up to hundreds of thousands of times, even millions of times; easy to realize mechanization and automation. 3. excellent economic effect due to casting precise size, smooth surface. The advantages of the pan general no longer mechanical processing and direct use, or processing capacity is very small, so it improves the utilization rate of the metal, and reduce the processing equipment and a large number of working hours; the price of the casting is easy; can be used in combination with his metal casting Or non metal materials. Not only save assembly time and save metal die-casting. Although there are many advantages, but there are also some shortcomings, need to be solved. Such as: 1. die casting of the liquid metal filling cavity of high speed, flow instability, so the general casting method, the casting is easy to produce pores, can not heat treatment;
Pressure casting (referred to as casting) is the essence of under high pressure, the liquid or semi liquid metal filling velocity in high pressure mold cavity, and forming under pressure and solidification and casting method. The characteristics of high pressure and high pressure die casting mold filling is the two characteristic of die casting. It commonly used injection the pressure is from thousands to tens of thousands of kPa, even as high as 2 * 105kPa. filling rate is about 10~50m / s, sometimes even up to 100M / S. The filling time is very short, generally in the range of 0.01~0.2s. Compared with other casting methods, die casting has the following three advantages: good quality products with high precision casting size 1.. The general equivalent of 6~7, even up to 4; surface finish, generally equivalent to 5~8; the hardness and strength of high strength than sand casting to improve 25~30%, but the elongation decreased about 70%; dimensional stability, good interchangeability; can Die casting complex thin-wall castings. For example, the zinc alloy die castings minimum wall thickness can reach up to 0.5mm 0.3mm; Aluminum Alloy castings; minimum cast diameter is 0.7mm; the minimum pitch for 0.75mm.
2. pair of concave complex casting, die casting is difficult; 3) of high melting point alloys (such as copper, ferrous metal), die life is low; 4) for small batch production, the main reason is the die manufacturing cost is high, the production efficiency of the die casting machine, small batch production of economy. The scope of application of die casting die casting and the trend of development is one of the most advanced metal forming technologies, is to achieve low chip, no effective way of chip, the application is very broad, is developing very quickly. Now no longer confined to the non-ferrous metal die-casting alloy zinc, aluminum, magnesium and copper, but also gradually expand To die casting iron and steel castings. The size and weight of die casting, power depends on the die casting machine. Because the power of die casting machine is increasing, the casting shape size from a few millimeters to 1 ~ 2m; the weight can be from a few grams to tens of kilograms. Overseas casting diameter is 2m, weight is 50kg of aluminum castings. Die casting is no longer confined to the automotive industry and instrument industry, and gradually expand to other industries, such as agricultural machinery, machine tool industry, electronic industry, defense industry, computer, medical instruments, watches, cameras and other dozens of daily hardware industry. In die casting technology appearvacuum die casting, die casting, finishing with oxygen speed close die casting and soluble core and the application of new technology.
