The History of Gravity Die Casting in Bolang

In 2000 year, we built our gravity die casting shop in our factory. There was only one gravity casting machine that time. Now we have four lines for gravity casting and can make 3000kg aluminum gravity casting per day. Our production is including auto components, subway components, gas station components, pipeline components, Wheel, fuel injection housings, spline.

Gravity Die Casting is named permanent mold casting or chill casting. Permanent mold is called in America, Chill cast or gravity casting is named in Europe.

The process is suitable for less quantity and high quality aluminum castings, the surface is better than sand casting. The material of permanent mold is steel, the mold is pre-heated up to 200¡æ before the aluminum alloy is poured into the cavity.

The weight range from 30g to 100kg/pcs, all thickness of parts must meet above 3.5mm, the draft angles must meet 1º to 3º on outside surface, 2º to 5º on inside surface.

At present, the aluminum gravity die casting is very mature in China.



Core mold

Description
If the internal structure of gravity die casting part is very complex, can not open mold, the engineer will make the core or sliding block to resolve it.


Making core

Description
1. AS usually, the material is resin sand, the "resin sand" consists of sand and synthetic binders cured thermally or chemically. The resin sand becomes very hard when it is heated by electricity.

Resin sand core

Description
2. After the resin sand core is more harder, we can take out it from mold. If necessary, the resign sand core must be dried. If so, it is free of the porosity in castings

Installing core

Description
3. Installing the cores on the mold.
In permanent mold casting or gravity casting, the mold material is cast iron and steel, or other metal alloys are treated and formed into two or more than two patterns of the mold.

Close and fixture mold

Description
4. Close and fixture mold is very important, so the worker must be skilled. The two or more than two patterns of the molds are usually clamped tightly together.

Pouring melt aluminum

Description
5. Pouring molten aluminum to 150-200 ¡ãC (300-400 ¡ãF) to ease the flow and reduce thermal damage to the casting. Molten aluminum is then poured into the mold through a gating system, which decreases the chance of impurities in the aluminum. Molten aluminum should be poured at the lowest practical temperature in order to minimize the possibility of cracks and porosity.

Opening mold

Description
6. Once the aluminum has solidified the molds are opened and the casting is removed. The mold is then either cooled, or heated for another chill casting.

Gravity die casting

Description
7. Taking out the gravity die casting from permanent mold, the working of mould is finished, the cutting the raiser and pouring, then machining.