Increasing the formability of magnesium alloy sheet

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The chief advantage of magnesium is a density that is much lower than aluminum and Mg alloy in sheet form is one of the main routes to increased usage in cars. However, the problem of using Mg sheet is its low room temperature formability, which could be overcome by adding suitable alloying elements and/or different approaches to making sheet and making components out of sheet. This proposal investigates three approaches to increasing sheet formability: (i) additions of neodymium, a rare earth element (REE), and calcium; (ii) specialized heat treatments of rolled sheet to appropriately soften the sheet before forming the component and (iii) softening the sheet during the component forming operation. The effect of REE in improving the microstructure of rolled Mg is well known but not well understood and far from optimised. Thus, this work will include an atomic level computational approach to understand the effects of REE and Ca, in order to design REE bearing alloys with lean chemistries. The specialized heat treatment approach needs specialized rolling to make the sheet. Therefore, the interplay between sheet rolling and subsequent heat treatment will be studied and modelled to maximise formability. Finally, softening of the sheet during the forming of a component from the sheet has never before been considered, but is made possible because the current forming approach subjects sheet to 'warm' temperatures (about 200 centigrade), and this opens up some really novel approaches to forming.This proposal includes all the important players to make the research transfer to real applications, since it is a collaboration between Magna International, a Canadian car parts manufacturer, INFINIUM a new 'green' materials producer that has Mg and REE in it's portfolio, CanmetMaterials a Canadian government laboratory with appropriate scale-up facilities and expertise and Oak Ridge National Laboratories, who will advise on the composition of optimized alloys from the viewpoint of corrosion resistance, which is the other major obstacle to using Mg sheet in cars.