Lightweight, High-Strength Nanocomposite Magnesium for Radiators

The next generation of radiators will be designed using a composite with the combination of the lowest density, highest thermal conductivity, and highest strength. A scalable, low-cost process was developed to advance state-of-the-art metal matrix thermal conductors to reach a theoretical goal of 578 W/mK (270W/mK achieved), a density less than aluminum (1.7g.cc achieved), and a yield strength over 30 ksi (≈207 MPa, 42 ksi achieved). The incorporation of nanofibers into metals has been heavily researched to improve mechanical and thermal properties of materials, with limited technical and commercial success. The problem of incorporating high-aspect-ratio, high-surface-area particles (including fiber and flake) with controlled and repeatable concentration and distribution into molten metals is a large undertaking, and must factor in the molten metal temperature, composition, and surface tension. Direct feeding of the particles does not work, as particles burn, react with the molten metal, or do not stay in the metal. Other feeding mechanisms such as auger feeding into the metal, in-situ formation, and stir casting are cost-prohibitive and not always scalable.