(die-casting) is a metal casting process that uses a mold cavity to apply high pressure to the molten metal. Molds are usually made of higher-strength alloys, and this process is somewhat similar to injection molding. Most die castings are iron-free, such as zinc, copper, aluminum, magnesium, lead, tin, and lead-tin alloys and their alloys. Depending on the type of die casting, you need to use a cold chamber die casting machine or a hot chamber die casting machine.
(1) Metal parts with complex shapes, clear outlines, thin-walled deep cavities can be manufactured. Because molten metal maintains high fluidity under high pressure and high speed, it is possible to obtain metal parts that are difficult to process by other processing methods.
(2) The dimensional accuracy of die castings is relatively high, up to IT11-13, sometimes up to IT9, the surface roughness reaches Ra0.8-3.2um, and the interchangeability is good.
(3) High material utilization rate. Due to the high precision of die-casting parts, they can be assembled and used only after a small amount of mechanical processing, and some die-casting parts can be directly assembled and used. The material utilization rate is about 60%-80%, and the blank utilization rate reaches 90%.
(4) High production efficiency. Due to the high-speed filling, the filling time is short, the metal industry solidifies rapidly, and the die-casting operation cycle speed is fast. Among various casting processes, the die casting method has the highest productivity and is suitable for mass production.
(5) Easy to use inserts. It is easy to set a positioning mechanism on the die-casting mold to facilitate the insert casting of the inserts and meet the local special performance requirements of the die-casting parts.
(1) Due to high-speed filling and rapid cooling, the gas in the cavity is too late to discharge, resulting in die castings often have pores and oxidized inclusions, thereby reducing the quality of die castings. Due to the expansion of the gas in the pores at high temperatures, the surface of the die-cast part will bubble, therefore, the die-cast part with pores cannot be heat treated.
(2) Die-casting machines and die-casting molds are expensive and not suitable for small batch production.
(3) The size of die castings is restricted. Large die-casting parts cannot be die-casted due to the limitation of die-casting machine clamping force and die size.
(4) The types of die-casting alloys are restricted. Due to the limitation of operating temperature, die-casting molds are currently mainly used for die-casting zinc alloy, aluminum alloy, magnesium alloy and copper alloy.
Forging (forging) is a processing method that uses forging machinery to apply pressure to metal blanks to produce plastic deformation to obtain forgings with certain mechanical properties, certain shapes and sizes. Forging (forging and stamping) is one of the two major components One. Forging can eliminate defects such as loose as-cast during the smelting process and optimize the microstructure. At the same time, due to the preservation of the complete metal streamline, the mechanical properties of forgings are generally better than those of castings of the same material. For the important parts of related machinery with high load and severe working conditions, in addition to simpler shapes that can be rolled, profiles or welded parts, forgings are mostly used.
Features of forging:
1. Improve the internal structure of the metal and improve the mechanical properties of the metal;
2. Have high labor productivity;
3. Wide application range. The quality of forgings is as small as less than 1kg and as large as hundreds of tons; it can be produced in a single piece and in small batches, as well as mass production;
4. The use of precision die forging can make the size and shape of the forgings close to the finished parts, so it can greatly save metal materials and reduce cutting processing hours;
5. Forgings with complex shapes cannot be forged.