4. Gravity die-casting and casting of zinc alloys

Zamak alloys were developed to be particularly suitable for die-casting, and it is in this mode of processing that they offer the greatest advantages.

Although it is possible to cast them by gravity in sand or metal shell molds, this technique presents a number of difficulties and, if the caster does not master all the casting parameters perfectly, the results can be disappointing. This explains the relatively modest development of gravity-cast zinc alloys in recent years.

To fill this gap, the International Lead And Zinc Research Organization (ILZRO) has studied and developed a new family of zinc-based alloys: ZA 8, ZA 12 and ZA 27.

The ZA 12, which appeared on the French market in 1970 under the name Ilzro 12, has developed exclusively in the field of gravity molding.

On the contrary, the...