Die casting is in the pressure chamber of the die-casti […]
Die casting is in the pressure chamber of the die-casting machine, pouring liquid or semi-liquid metal or alloy, it is high pressure and high speed filling cavity, and under high pressure molding and crystallization to obtain a casting casting method.
As the molten metal is subject to a high specific pressure, the flow rate is very high and the filling time is extremely short. High pressure and high speed is the two major characteristics of liquid metal filling process during die casting, and also the most fundamental difference between die casting and other casting methods.
Such as injection than the pressure in the range of several megapo to tens of megapascals, or even up to 500MPa; filling speed of 0.5-120m / s, filling time is very short, usually 0.01-0.2s, the shortest only a few minutes.
Die casting has the following advantages: 1) product quality is good. As the die-casting thermal conductivity fast, rapid cooling of the metal, while the crystallization under pressure, the casting has a fine grain structure, the surface solid, improve the strength and hardness of the casting, in addition casting size is stable, good interchangeability, Complex parts; 2) high productivity, die-casting mold use more; 3) good economic returns. The machining allowance of the die casting is small and generally only need to be finished and reamed, which saves a lot of raw materials, processing equipment and working hours.
Die casting is a rapid development of modern metal processing technology, a high efficiency, less cutting metal forming precision casting method, is a "good, fast, provincial" high economic double benefit casting method.
The shape of die-cast parts can be divided into six categories:
1) disc type - number plate seat;
2) dome cover - table cover, cover, chassis, etc.;
3) rings - connectors, bearing holders, steering wheel, etc.;
4) cylinder type - flange jacket, catheter, shell shape of the cover, cover, instrument cover, probe instrument cover, camera case and carburetor, etc.;
5) porous cylinder, shell - cylinder block, cylinder head and pump body and other multi-cavity structure of the more complex shell . Such as car and motorcycle cylinder block, cylinder head;
6) special shape - impeller, speakers, the font composed of ribs, such as decorative die casting