Month: February 2010

A new magnesium die cast support structure for an automatic-dimming rear view automotive mirror is now being produced in a high-pressure, hot-chamber Mg die casting machine using “in-die de-gating,” two-stage ejection technology, resulting in significant cost savings.

This new Mg production strategy is based on established miniature zinc die casting production techniques. The successful application to larger high-pressure, hot-chamber Mg custom die casting equipment has significantly reduced post-casting operation costs and brought CWM the 2009 “Award of Excellence” for Process Innovation from the International Magnesium Association.

In moving to a lightweight, yet strong, mag die casting for a new model of their advanced electrochromic mirror’s structural component, Gentex company engineers put forth a unique challenge for the die design and production of their new unit. They called for a new Mg tooling design that could achieve the post-casting cost-savings of the high-speed miniature zinc die casting process in the 200-ton hot-chamber mag die casting machine required for the part.

Chicago White Metal brought its deep experience in hot-chamber magnesium part design and production, as a North American pioneer in the process, to bear on the project. CWM was joined by another Gentex supplier, Cast Products, with its background in tooling design for miniature zinc die cast parts.

The Mg die casting is now being produced without the use of a trim die– no final trimming required. This new application story is being featured in recent issues of Design News and Machine Design magazines.

More details, and photos, on this advance in Mg die casting process technology, go to “Case Study #41.”