Die cast is a kind of metal forming process that enables mass production for complicated shaped metal parts / components.
And die cast also means such parts / components produced by die cast process.
Materials used for die cast are very varied, such as alloy based on aluminum, zinc, brass, tin or magnesium.

Minimum elements of die cast process are from
-          Tool (die) specially fabricated to produce a shape of parts. A tool can produce mass of same parts in its life.
-          Furnace to melt material to be cast into tool.
-          Die cast machine to attach a tool and has function to cast molten material into the tool.
 
We, OS-TEC (M) SDN. BHD. currently uses only aluminum alloy to produce parts / components for customers.
ADC12, a kind of aluminum alloy is very popular for die cast worldwide.

This page is prepared with our intention of supporting mechanical design activities for potential customers looking for opportunity to adopt aluminum die cast parts in their products.

In mechanical design activities, at first, mechanical property of used material is important, to study suitability to your products.

Tensile strength of aluminum is higher than zinc, magnesium and plastics.
It keeps very small stretch, and contributes high dimensional accuracy and stability.

Aiming better strength of parts in your components, aluminum die cast may help replacing zinc or plastics.

Compared to steel, zinc alloy or copper, aluminum is lighter in weight, and heavier than magnesium or most of plastics, respectively in same volume.

Dimensional accuracy of die cast is good and it can avoid complicated additional processes after the process.
Even additional process is necessary to obtain higher accuracy, simple and fast machining process can help it.

Aluminum has high heat transferring property.
So that application as heat sinks for heat source such like IC is suitable, with forming ventilation fins by die cast process.

Have you seen steel products rusty in black or red? I believe yes.
That is a result of oxidation grown in time being.
Aluminum is very corrosive. But the reaction is happened in very short moment on only limited thin layer.
Once such thin oxidized layer has been built, it protects inside from further corrosion.
It almost means that aluminum has self-protection against corrosion.

A tool is fabricated for one shaped part, in principal.
Using some exchanging tool parts may produce little variation of parts with one tool.
Cavity can be one, two or more multi number in a tool, within capacity of die cast machine.
It means that one cycle of die cast process can produce one or multi number of parts in same time.
Number of cavity highly affects speed of production, mass quantity in tool life, and also tool cost.

Practical minimum thickness of part formed by die cast is around 1.5mm, depending to whole shape, freedom of tool design, material used or visual / dimensional requirement on the part.

Molten cast aluminum shrinks when it gets cool and solidified in the tool.
Shrinkage of aluminum leaves or catches tool surface, result to unable to be released from the tool.
It is one of reasons to add taper on tool surface.

Die cast parts need taper (draft angle) along friction direction between parts and tool.
Taper is formed in tool as slight tilt wall of cavity.
Bigger angle taper can ease productivity, but amplify dimensional bias bigger from ideal shape.
It will be a discussing point between customers that balancing allowable dimensions bias and productivity.

Round, rectangular or complicated shaped hole could be formed with core inserts, which are exchangeable to maintain right shape and dimension.

A tool has minimum 2 main pieces as its structure, called fixed die (cavity) and moving die (core).
Those cavity and core faces each other and fit at “parting line” when die set is closed.
Injection of molten material is performed when die set is closed.
Inside of die set, material is cooled and solidified and ready to be a product.