Alloy 380 is the most common of the
aluminum die casting alloys. It offers the best
combination of casting and product properties.
It is used for a wide variety of products such
as garden equipment, chassis for electronic
equipment, engine brackets, housings for
automotive alternators, starters and water
pumps, home appliances, furniture, office
eqipment hand tools and power tools.
Alloys 383 and 384 are alternatives to
380 that are specified when very intricate
components require improved die filling
characteristics and improved resistance to hot
cracking.
Alloy 360 offers high corrosion
resistance and superior strength at elevated
temperatures than 380. Other properties are
essentially equivalent.
Alloy 413 offers the best die fill
characteristics making it excellent for pressure
tightness applications. it is the choice for
products such as hydraulic cylinders and
pressure vessels. Its casting characteristics
make it useful for very intricate components.
Alloy 390 was developed for automotive
engine blocks. Resistance to wear is excellent,
but ductility is the lowest of the die casting
alloys, with elongation less than 1%. Special
surface treatment systems allow engine engine
pistons to run directly on the alloy surface,
eliminating the need for ferrous alloy liners.
It can also be used for valve bodies and bearing
surfaces subject to abrasion and wear.
Alloy 518 is used in escalator
components, conveyer components, and marine and
aircraft applications It offers good ductility,
and very good corrosion resistance. It can be
polished and anodized for a decorative finish.
Zinc Die Casting Alloys
Zamak #3 is the standard for
the zamak series of zinc alloys;
all other zinc alloys are
compared to this. Zamak 3 has
the base composition for the
zamak alloys (96% zinc, 4%
aluminium). It has excellent
castability and long term
dimensional stability. More than
70% of all North American zinc
die castings are made from zamak
3.
ZAMAK #5 offers high tensile strength,
harness, and creep resistance than zamak# 3, and
somewhat lower ductility. It is preferred
whenever these properties are required. Some die
casters use only zamak# 5, which is usually an
acceptable alternative to zamak# 3.
ZAMAK #7 is essentially a high purity
form of zamak# 3 with slightly higher ductility
and lower hardness. The other mechanical
properties are identical to zamak# 3. The alloy
also exhibits higher fluidity than zamak# 3 or3
5, which theoretically allows slightly thinner
walls. Zamak# 7 may be specified when high
ductility is required.
ZA-8
is rapidly growing in popularity for pressure
die casting. ZA-8 can be cast in hot chamber die
casting machines for fast cycle rates, It has
improved strength, hardness and creep properties
over the ZAMAK alloys with the exception of a
No. 2 alloy which is very similar in
performance. ZA-8 is readily plated and finished
using standard procedures for ZAMAK. When the
performance of Zamak No. 3 or No. 5 is in
question, ZA-8 is often the die casting choice
because of high strength and creep properties
and efficient hot chamber castability.
ZA-12
is also a good pressure die casting alloy, using
the cold chamber process, which provides a
sounder structure than ZA-27, as well as higher
die cast elongation and impact properties. For
these reasons, die cast ZA-12 often competes
with ZA-27 for strength application. An
excellent bearing alloy, ZA-12 is also platable,
although plating adhesion is reduced compared to
the ZAMAK alloys.
ZA-27 is the
high strength performer of the zinc alloys and
is die cast using the cold chamber process.. It
is also the lightest alloy and offers excellent
bearing and wear resistance properties. ZA-27,
however, requires care during melting and
casting to assure sound internal structure,
particularly for heavy wall sections. It may
also need a stabilization heat treatment when
tight dimensional tolerances are required. ZA-27
is not recommended for plating. However, when
brute strength or wear resistant properties are
needed, ZA-27 has demonstrated extraordinary
performance.
