The difference between high pressure casting and low pressure casting.
1. The essence of high-pressure casting (referred to as die-casting) is to make liquid or semi-liquid metal fill the cavity of the #die-casting mold (die-casting mold) at a high speed under the action of high pressure, and form and solidify under pressure to obtain castings. Die casting has two characteristics of high pressure and high speed filling #die casting. Its commonly used injection pressure is from thousands to tens of thousands of kPa, or even as high as 2 × 105kPa. The filling speed is about 10~50m/s, sometimes even more than 100m/s. The filling time is very short, generally in the range of 0.01~0.2s.
In the case of low pressure casting:
(1) The pressure and speed during pouring can be adjusted, so it can be applied to various casting molds (such as metal molds, sand molds, etc.), casting various alloys and castings of various sizes.
(2) The bottom injection type filling is adopted, the metal liquid filling is stable, and there is no splash phenomenon, which can avoid gas involvement and scouring of the mold wall and core, and improve the qualification rate of castings.
(3) The #casting crystallizes under pressure. The #casting has a dense structure, clear outline, smooth surface and high mechanical properties, which is especially beneficial for the casting of large and thin-walled parts.
(4) The feeding riser is omitted, and the metal utilization rate is increased to 90-98%.