“Opportunities and Challenges for Implementing Magnesium to Reduce Weight in Transportation Applications”
Alan I. Taub, Ph.D.
University of Michigan
Professor, Materials Science & Engineering and Mechanical Engineering
Chief Technology Officer, Lightweight Innovations for Tomorrow
Today’s land, sea and air transportation industries – as a business necessity – are focused on technology solutions that will reduce vehicle weight to save energy as well as increasing payload and improving performance. The potential weight reductions from substituting lightweight metals (advanced high-strength steels, aluminum, magnesium and titanium alloys) are well established. For magnesium castings, weight savings of 60% have been reported. Improved manufacturing processes for magnesium in both cast and wrought forms are required to expand the alloy utilization. The Manufacturing USA institute Lightweight Innovations for Tomorrow (LIFT) is addressing the challenge to optimize the material properties and develop robust, high volume, manufacturing technologies and the associated supply chain to fabricate components and subsystems at the appropriate cost for each application. A key enabler for advancing the technology is ICME models that can support both the design and certification/validation phases of the work.
Magnesium Alloy Design and Process Development Using Integrated Computational Materials Engineering (ICME) Approaches
Alan A. Luo
The Ohio State University, Columbus, OH 43210, USA
This talk presents examples of magnesium alloy design and process development using Integrated Computational Materials Engineering (ICME) approaches. The talk will first demonstrate how CALPHAD (CALculation of PHAse Diagrams) modeling, when combined with critical experimental validation, can be used to guide the design of new magnesium alloys. The talk will then summarize some of the latest process innovations in cast and wrought magnesium products and the use of ICME in developing/optimizing these processes. This talk will also identify some of the gaps in using ICME tools in magnesium product design and applications.
Understanding the stacking faults and long periodic stacking ordered phases in Mg alloys
Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
e-mail: [email protected]
Co-authors: Hongyeun Kim, William Yi Wang, Kristopher A. Darling, Laszlo J. Kecskes
Stacking faults in hcp Mg alloys represent the local fcc atomic environment in a hcp matrix. Their periodic assembling in space results in the formation of long periodic stacking ordered structures (LPSOs). Our recent computational works in terms of first-principles calculations on the electronic structures of stacking faults and LPSOs and the effects of alloying elements on them will be discussed in this presentation. The transition of local atomic environment from hcp to fcc is observed through ab initio molecular dynamic simulations when alloying atoms are clustered. Furthermore, free energies of LPSO phases are obtained from finite temperature first-principles calculations and used to model their thermodynamic properties and predict their phase stability as a function of temperature and composition.
Magnesium Alloy Design
Magnesium alloys offer a number of advantages compared to other materials. They are easy to cast and to machine, their specific strength is superior and they can be easily recycled. However, for applications they have to fulfill certain requirements. According to the chosen applications, alloying elements and processing routes have to be selected carefully. On selected examples we will show how alloying elements affect processing and resulting properties.