The American Foundry Society’s Magnesium Division 6 research committee presented new developments in magnesium heat-treatment cycles, which it says may lead to significantly lower costs of magnesium cast components.
It was previously noted that magnesium alloys typically require long solution and aging cycles to achieve desired mechanical properties, adding increased costs to castings.
Eck Industries of Manitowoc, WI, and Technomics LLC of Plymouth, MN, began the preliminary investigation into fluidized-bed heat treatment of magnesium alloys in January. They examined methods to reduce cycle times.
Magnesium alloy AZ91E was selected for this development due to its common use in many markets, usually requiring a solution and age heat treatment of 32-40 hours.
Using a combined solution and aging time as low as 8-10 hours, the minimum requirements of the alloys mechanical properties were met. By heat treating in a shorter time from, the costs can be 33% less their current costs, and less than the costs of conventionally heat-treated aluminum castings.
The committee plans to investigate further into improving the new heat-treat development. Eck and Technomics have planned additional cycle development work to maximize mechanical properties of the alloy, and other magnesium alloy systems.