Mini-guide about die casting methods and metal injection molding. Visit: http://www.dynacast.com

1. Die Casting and Metal Injection Molding
Die casting and metal injection molding is an important part of the manufacturing process of certain
metal parts. Often these metal components are used for precision industries such as manufacturing
automobiles. The greatest investment is the initial die casting tool to create specific parts. Otherwise,
the process is an affordable way to produce essential metal components.
To learn more about die casting and metal injection molding, please visit http://www.dynacast.com or
continue reading below.
What is Die Casting?
During die casting, a molten metal is forced into a mold cavity with high pressure. Two hardened steel
dies are machined to create the mold cavity. A hot or cold chamber is used based on the type of metal
being cast. There is high pressure and low pressure die casting. About half the die cast metal parts
made use high pressure die casting and about one-fifth use low pressure die casting. Other types of
die casting are pore-free to get rid of gas porosity defects and direct injection to reduce the scraps
created when using zinc. There are four main steps to die casting. The results are components with a
smooth surface finish that are dimensionally consistent. The process of die casting was invented in
1838 and first patented in 1849. The goal is to make intricate parts affordable by creating them in
volume.
Common Types of Metals Used in Die Casting
Most of the metals used in die casting and metal injection molding are non-ferrous though an
uncommon form of ferrous die casting is sometimes done. Commonly used die casting alloys, besides
brass and bronze, include:
 Zinc lasts for a long time and is the easiest type of metal to cast because it its ductility, strength
and affordability;
 Magnesium happens to be the easiest metal to machine as well as the lightest alloy;
 Aluminum is also lightweight, resists corrosion, has great electrical and thermal conductivity
and can be shaped into thin walls that are still resistant to high temperature;
 Tin and lead are dense and used for specific types of corrosion resistance; and
 Copper is high, resists corrosion and wear and is almost as strong as steel parts.
Hot Chamber Die Casting Machines
Hot chamber is one of the two major types of die casting. These machines are also called gooseneck
ma machines. Ratings are given based on the clamping force of the machines, usually ranging between
400 and 4,000 st. In a hot chamber machine, a pool of hot molten metal is used to fee the die through
the gooseneck area. The metal gets forced through to the die. It is a fast process but certain metals
such as aluminum cannot be used because they pick up iron in the pool. Hot chamber die casting is
usually used with tin, lead-based alloys and zinc.

2. Cold Chamber Die Casting Machines
Cold chamber die casting machines are the second type of die casting machines. With these machines,
the metal is melted in a separate furnace then a specific amount is put into the cold chamber and
driven into the die using a piston. It is a slower process because the metal must be taken from the
furnace to the die casting machine. Cold chamber die casting is done with metals such as zinc alloys
and copper.
The Four-Part Process of Traditional Die Casting
Basically speaking, traditional die casting is a four-part process. Traditional die casting is also called
high pressure die casting. This is how the process is done:
 First, a lubricant is sprayed on the mold cavity to prepare the dies. This will help control the
temperature and make it easier to remove the casting.
 Second, the dies get closed and high pressure is used to inject the molten metal into the dies.
The cavity is filled and pressure put on until the casting is solid.
 Third, the dies are opens then shot out using ejector pins to eject the castings.
 The fourth and final step is called shakeout. The scrap is separated from the shop by a special
trimming process. Sometimes grinding and sawing are used as well as tumbling. The scrap is
re-melted to use again.
There are other features that are not part of the die casting process. Sometimes a hole is tapped into
the casting. Other times it is painted, polished, buffed or plated.
Metals Used to Make Parts
Die casting is done to create essential metal parts for an array of manufacturing industries. They
require the precision and smoothness of parts that are die casted. This is also a way to ensure the
parts are consistent, smooth and economical. Consider how various metals are used after the die
casting process:
 Aluminum castings are used often in the automotive industry for parts such as pistons, wheels,
brake cylinders and more.
 Zinc components are used for door handles, faucets, appliances, hairdryers and more.
 Magnesium is used for a wide variety of parts because it is lightweight and affordable.
Die Casting over Other Processes
Die casting has been around for a long time and will continue to be a major part of the metalworking
industry. Die casting is preferable over other processes for many reasons.
 Die casting produces stronger parts that resist higher temperatures than parts made through
plastic molding.
 Die casting makes parts with thinner walls, smoother surface areas and more accurate

3. dimensions than permanent mold or sand casting. It is also quicker and more affordable.
 Die casting can be used to produce unique shapes with multiple variations, unlike stampings.
 Die casting can make complex shapes for less money than forging and also make it possible to
include cast coring holes.
 Die casting can work with tubular stock and make odd shapes without adjustments to minimize
the scrap and waste that is commonly produced by screw machine products.
Die casting and metal injection molding continues to be the top way to produce many components
that are strong, temperature resistant and budget-conscious. Metalworkers and leading die cast and
MIM companies will be using die casting machines for years to come to keep industries such as
plumbing and automotive parts moving forward.