ASTM International’s committee on nonferrous metals and alloys (B02) is proposing two new standards. One is for a zinc-aluminum-copper alloy with improved strength. The other seeks to determine the requirements for die castings with thin walls, which can help reduce industry costs.

According to ASTM International, these proposed standards will be most useful to manufacturers and buyers of zinc die castings and can be used in multiple applications, including hardware.

The first proposed standard (WK 63461) is for an alloy that could  improve the elevated temperature strength compared to standard zinc die casting alloys while also improving castability. Creating the standard will involve a review of the literature and data from work previously initiated by the International Lead Zinc Research Organization (ILZRO) and the Council for Scientific and Industrial Research (CSIR). It will also include a review of data from other commercial alloys related to this work

The second proposed standard (WK 63462) will serve as a companion to an existing standard for high fluidity zinc alloy, (B989). It will provide composition requirements and consolidate the available physical and mechanical properties of these castings.

“The ability to produce strong zinc castings with thin walls results in material savings and reduced secondary machining due to the superior net-shape capability of zinc casting,” says member and committee chairman John Malmgreen, vice president, manufacturing and quality, Eastern Alloys.

The value of these products, he says, also stems from their lighter weight and superior finish. Although the composition of the alloy is defined in B989, the deviations allowed for castings and the expected physical and mechanical properties are not, thus requiring the new standard.