Nano Magnesium

Magnesium-based alloys are among the lightest of all structural metals. They have excellent strength (or stiffness)-to-weight ratio and are cost-effective in engineering applications. Microstructural modifications can be achieved by improvements in the techniques used to process the alloy. This has led to extensive studies of property enhancements, particularly elevated strength, induced by tailoring the microstructure. For example, a Mg₇₀Al₂₀Ca₁₀ alloy with a tensile yield strength of 600 MPa and a Mg₈₆Al₉Ca₅ with a compressive fracture strength as high as 727 MPa have been prepared by extrusion consolidation of gas-atomized powders. The high strength was derived from the ultrafine and nanocrystalline grain structures achieved in the consolidated alloys. 

Fine microstructures can also be induced by increasing the growth velocity (or cooling rate) during solidification of liquid into bulk ingots. An alternative route to a better combination of strength and ductility is via in-situ formed composites composed of a nano/ultrafine eutectic matrix and a ductile dendritic primary phase.  Generally, a eutectic matrix with ultrafine lamellar spacing is already rather strong; what it needs is an improved ductility and toughness, which can be derived from an embedded ductile phase (or the same phase but larger grain size such as in a bimodal grain size distribution).

Long-Range Objectives

· Determine the potential of nanostructured magnesium alloys for armor applications.

· Examine the issues of formability and corrosion resistance of nanostructured magnesium alloys and their composites.

Molecular Dynamics simulation of magnesium deformation

Nanocrystalline magnesium alloys

CRG