Zamak also known as Zamac. Zinc Die Casting Alloys or Zinc Alloys For Die Casting
Zamak can be electroplated, wet painted, and chromate conversion coated well. Zamak has high strength and hardness lends itself to many solutions.
Zamak KS alloy was developed for spin casting decorative parts. It has the same composition as zamak 2, except with more magnesium in order to produce finer grains and reduce the orange peel effect.
Zinc alloy 2 has the same composition as zamak 3 with the addition of 3% copper in order to increase strength by 20%, which also increases the price. ZL0430 has the greatest strength out of all the zamak alloys. Over time it retains its strength and hardness better than the other alloys; however, it becomes more brittle, shrinks, and less elastic.
ZL 2 is also known as Kirksite when gravity cast for use as a die. It was originally designed for low volume sheet metal dies. It later gained popularity for making short run injection molding dies. It is also less commonly used for non-sparking tools and mandrels for metal spinning.
Zamak 3 is the de facto 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.
Zamak 3 also offers excellent finishing characteristics for plating, painting and chromate treatments. It is the “standard” by which other zinc alloys are rated in terms of die casting
Zamak 4 was developed for the Asian markets to reduce the effects of die soldering while maintaining the ductility of zamak 3. This was achieved by using half the amount of copper from the zamak 5 composition
When compared to Zamak 3, the mold sticking problem is improved and the flexibility remains unchanged. It is commonly used to produce clothing accessory such as zipper pulls and zipper sliders.
ZL0410 has the same composition as zamak 3 with the addition of 1% copper in order to increase strength (by approximately 10%), hardness and corrosive resistance, but reduces ductility. It also has less dimensional accuracy Zamak 5 is more commonly used in Europe.
Coating capability is good. It has few errors of dimension. It is especially used in accessories and automobile industry.
Zamak 7 has less magnesium than zamak 3 to increase fluidity and ductility, which is especially useful when casting thin wall components. In order to reduce inter-granular corrosion a small amount of nickel is added and impurities are more strictly controlled.
ZL 7 proved casting fluidity, ductility and surface finish.
Higher fluidity is sometimes desirable especially on components with intricate detail, however it does present special casting considerations
A good gravity casting alloy, Zamak 8 is rapidly growing for pressure die casting. ZA-8 can be hot chamber die cast, with improved strength, hardness and creep properties over ZAMAK’s, with the exception of a zamak 2 alloy which is very similar in performance
ZA-8, or zinc aluminum alloy, contains significantly more aluminum than the Zamak group of alloys. ZA-8 contains approximately 8.4% aluminum and is the only ZA alloy that can be hot-chamber die cast, an important consideration when selecting a material for a component
Zamak 12 is the best gravity casting alloy for sand, permanent mold and the graphite mold casting process. It is also a good (cold chamber) die casting alloy.
ZA-12 is the most versatile zinc alloy in terms of combining high performance properties and ease of fabrication using either gravity or pressure die casting
For these reasons, die cast ZA-12 often competes with ZA-27 for strength application. An excellent bearing alloy, ZA-12 is also palatable, although plating adhesion is reduced compared to the zinc alloys
Zamak 27 contains 27% aluminum content and is the strongest of the Zamak series.
Zamak 27, or zinc aluminum alloy, contains significantly more aluminum than the Zamak group of alloys. The number 27 represents the approximate percentage of aluminum
It is extremely difficult to handle and has poor die filling characteristics, which can be offset by simplifying the casting design.
ZA27 is 40% stronger and harder than typical aluminum die cast alloys and also offers bearing properties not seen in other alloys
|Chemical (in%)||Zamak KS||Zamak 2||Zamak 3||Zamak 4||Zamak 5||Zamak 6||Zamak 7||Zamak 8||Zamak 12||Zamak 27|
|Al||3,9 - 4,3||3,8 - 4,2||3,8 - 4,2||3,9 - 4,3||3,8 - 4,2||5,6 - 6,0||3,9 - 4,3||8,2 - 8,8||10,8 - 11,5||25,5 - 28,0|
|Cu||2,7 - 3,3||2,7 - 3,3||≤0,03||0,3 - 0,5||0,7 - 1,1||1,2 - 1,6||≤ 0,1||0,9 - 1,3||0,5 - 1,2||2,0 - 2,5|
|Mg||0,4 - 0,6||0,035 - 0,06||0,035 - 0,06||0,03 - 0,06||0,035 - 0,06||≤0,005||0,01 - 0,02||0,02 - 0,03||0,02 - 0,03||0,012 - 0,020|