The process is conducted in a automatic machine suitable to resist high-pressure.
The molten metal is pushed by way of a hydraulically actuated plunger into a two-piece steel die containing more than one cavities, each a precise inverse replica in the part or parts being produced. As a result of quick chill and rapid solidification which takes place when molten metal comes in contact with the relatively cool steel side, and also since the fine metallurgical grain structure that results, the mechanical properties of pressure die castings are generally preferable over castings created by other methods.
Zinc pressure die castings, by way of example, are stronger than sand cast CNC precision machining, SAE 40 bronze, and sophistication 30 cast iron. Also, pressure die cast components produced using the ZA alloys are stronger than pressure die cast aluminum 380 alloy.
The name “ZAMAK” is an acronym through the German words that comprise the alloys primary ingredients: Z (zinc) A (aluminum) M (magnesium) and K (copper). Once the alloys were,developed in the 1920s the very first useable material was designated Zamak #1. With every subsequent iteration, the designations increased sequentially (1-2-3-4-5-6-7); simply the most desirable alloys (2-3-5-7) remain in use presently.
The name ZAMAK is an acronym from your German words that make up the alloys main ingredients…
Zamak 2, a predecessor of your more traditionally used Zamak 3, provides the highest strength and hardness from the 4% zinc, aluminum (Zamak) alloy family. Simply because of its relatively high copper content (3%), it is actually approx. 25% stronger, as cast, than Zamak 3, and almost 10% stronger than Zamak 5, with higher hardness than both.
The top copper content, however, leads to property changes upon long term aging. These changes include slight dimensional growth (.0014in/in after 20yrs), lower elongation and reduced impact performance (to levels just like aluminum alloys) for die cast products. It does, however, provide some interesting characteristics which may assist designers. Its creep performance is rated more than one other Zamaks and #2 maintains higher tensile, strength and hardness levels after long term aging. Also, preliminary investigations suggest #2 is a great bearing material and may even eliminate bushings and wear inserts in die designs.
However it does give up impact strength and due to this limitation Zamak 2 is just used once the strength or hardness of Zamak 3 or 5 will not be sufficient for too long-term end use. Zamak 2 might be termed as Kirksite and is the only alloy used for gravity casting – mainly for metal forming dies or plastic injection molds.
ZAMAK 3 Of all of the zinc casting alloys, Zamak 3 is the most traditionally used, accounting for approx. 85% ofall zinc casting tonnage worldwide. They have the base composition for those die casting parts alloys (96% zinc, 4% aluminum). Its superb physical and mechanical properties, excellent castability and long term dimensional stability give you the basis for its broad usage. The convenience it could be electroplated adds to the demand for this alloy, with excellent finishing characteristics 21dexupky plating, painting, and chromate treatments. This is basically the “standard” where other zinc alloys are
rated when it comes to die casting and is, therefore, by far the most widely available alloy for die, casting sources.
Zamak 2, has got the highest strength and hardness within the 4% zinc, aluminum alloy family.
Generally through casting design procedures, a Zamak 3 pressure die casting can be created to fulfill service or functional requirements. When this is simply not the situation, especially where strength is concerned, CNC precision machining is definitely the next choice. Aside from a nominal 1% copper addition, the chemistry of Zamak 5 is similar to those of Zamak 3. The composition modification brings about higher tensile strength and increased hardness, but sacrifices elongation. Zamak 5 has significantly better creep resistance compared to other alloys within the conventional group.
Zamak 5 is just not as ductile as a number of the other alloys, an aspect to consider when post casting operations such as secondary bending, riveting, swaging or crimping are essential. As a result of 3’s wide availability, material specifiers often strength components by design modification as an alternative to Zamak 5. However, when another measure of tensile performance is necessary,
Zamak 5 castings are recommended. The alloy is easily plated, finished and machined, and resembles Zamak 3.