The Zamak is an alloy of Zinc, Aluminum and Magnésium and sometimes of Cuivre. Its name is a Acronyme names German S of metals which compose it: Z for Zink (zinc), has as an Aluminum, MY for Magnesium (magnesium) and K for Kupfer (copper).

The average proportions for the realization of alloy are of zinc 95%, of 4% of aluminum, 1% of copper and approximately magnesium 0,03%. Its melting point is of approximately 400° C. It is an alloy resistant and easy to work. It does not oxidize and is ideal for the Moulage under pressure because it has a very good Fluidité. It is used in the car, the small mechanical engineering, the toy and the bimbelotery.

Good resistance to the gasoline of oil, the engine oil, the alcohols, the Trichloroethylene.

It can deteriorate with time: the zamac of the years 1950 frequently falls in dust.

Zamak in industry

Rapid prototyping

The rapid prototyping of parts in Zamak is done according to the process of vacuum casting said “to lost Cire”. Starting from a file 3D of the part (step, iges, native…) the prototypist directs the part in space in order to optimize his realization and sends this file towards a machine of rapid prototyping (multiple jet modelling, powder sintering, stereolithography) which will create the wax part.

This part is slightly worked over again (with the hand) by the prototypist who will add “the funnel to it” and, according to the typology of the part, of the vents, before putting it in a tank which one fills with Plâtre. After a cooking of a few tens of minutes with 120° C which allows a hardening and a drying of the plaster, as well as the evacuation of wax, the mould thus obtained is introduced into a machine of vacuum casting. The mould is in the low part, Zamak (Ilzro 12) is in a heating tank located in the upper part. Closing of the machine, the vacuum is made (that makes it possible to have an optimum filling of the print), then run of Zamak by gravity.

After cooling the mould is broken and the recovered part. The completion (fettling, put at the dimension) is made with the hand.

It is also possible to create a mould which will be useful for the parts in series because the zamac is very much used in particular for the creation of stoppers of perfume.

Pressure injection

Zamak lends itself well to the pressure injection hot room and thus makes it possible to carry out parts of a good precision with a short cycle time (from 10 to 40 seconds).

The disadvantage lies in the gas imprisonment in the part which can emerge, either with the release from the mould, or during a heat treatment of the part (put in painting then cooking).