Magnesium is plentiful, environmentally safe, strong and lightweight, making it an ideal material for use in aerospace and automotive applications. But to reliably use magnesium alloys, which are mixtures of magnesium and small amounts of other metals, in product designs, engineers have to understand how the material will hold up under the stress and wear that real-life products endure. And that's been a challenge.
A new research project in the Mechanical Engineering Department seeks to investigate that question. The $340,000 grant from the National Science Foundation will fund work by Yanyao Jiang, professor of mechanical engineering, into how magnesium stands up to repeated loading.
"A basic study is needed due to the difference of magnesium's microstructures from these of other engineering materials," Jiang said. "Existing magnesium alloys are easy to corrode and combustible. New magnesium alloys should be developed to have higher resistance to corrosion and fire."
Magnesium displays specific deformation behavior, or ways of breaking or changing shape, that differs from most of the other materials typically used in engineering applications. A major difference between a conventional metal and a magnesium alloy is the deformation phenomenon of mechanical twinning, where the crystal structure rapidly changes orientation, which can make a material more susceptible to breakage.
Jiang's three-year award, titled Experimental Study of Cyclic Plastic Deformation Mechanisms in Hexagonal Close-Packed (HCP) Magnesium, will subject magnesium crystals oriented along different directions to various cyclic loading conditions and microscopically examine the crystal structure and deformation under loading.
Jiang's study will provide insight into the quantitative relationship between the applied load and the material deformation, the dependence of the deformation behavior on the crystal orientations, and the relationship between the material performance and the microstructures inside the material.
"The results from the project will provide a benchmark for development and validation of magnesium deformation models at different scales, paving the way for incorporation of magnesium alloys into engineering design," said Jiang.
