Die Casting Manufacturer India

Die Casting is the process of forcing molten metal under high pressure into the cavities of steel moulds.
The moulds are called dies. Dies range in complexity to produce any non-ferrous metal parts (that need not be as strong, hard or heat-resistant as steel) from sink faucets to engine blocks (including hardware, component parts of machinery, toy cars, etc).

In fact, the process lends itself to making any metal part that must

1. be precise (dimensions plus or minus as little as .002 inches--over short distances)
2. have a very smooth surface that can be bright plated without prior polishing and buffing,
3. have very thin sections (like sheet metal--as little as .050 inches),
4. be produced much more economically than parts primarily machined (multi-cavity die casting moulds operating
at high speed are much more productive than machine tools or even stamping presses)
5. be very flexible in design; a single die casting may have all the features of a complex assembly.
If several machining operations would be required or assembly of several parts would be required (to make a
finished part), die casting is probably far more economical. This level of versatility has placed die castings among the highest volume products made in the metalworking industry.

Common metals used in die casting include zinc and aluminum. These are usually not pure metals; rather are alloys which have better physical characteristics.

In recent years, injection-moulded plastic parts have replaced some die castings because they are usually cheaper (and lighter--important especially for automotive parts since the fuel-economy standards). Plastic parts are practical (particularly now that plating of plastics has become possible) if hardness is not required and if parts can be redesigned to have the necessary strength.

There are four major steps in the die casting process.

First, the mould is sprayed with lubricant and closed. The lubricant both helps control the temperature of the die and it also assists in the removal of the casting.

Molten metal is then injected into the die under high pressure. The high pressure assures a casting as precise and as smooth as the mould. Typically it is around 100 megapascals.

Once the cavity is filled then the pressure is maintained until the casting has become solid (though this period is usually made short as possible by water cooling the mould).

Finally, the die is opened and the casting is ejected.

Equally important as high-pressure injection is high-speed injection - required so the entire cavity fills before any part of the casting solidifies. In this way, discontinuities (spoiling the finish and even weakening the casting) are avoided even if the design requires difficult-to-fill very thin sections.

Before the cycle can be started the die must be installed in the die casting machine (set up) and brought to operating temperature. This set-up requires 1-2 hours after which a cycle can take anywhere between a few seconds to a few minutes depending on the size of the casting. Maximum mass limits for magnesium, zinc, and aluminium parts are roughly 4.5 kg, 18 kg, and 45 kg, respectively.

A typical die set will last 500,000 shots during its lifetime with lifetime being heavily influenced by the melting temperature of the metal or alloy being used. Aluminum and its alloys typically shorten die life due to the high temperature of the liquid metal resulting in deterioration of the steel mould cavities.