A thermally stable and strong Mg-MgF2 nanocomposite

Nanocrystalline Mg is often strong but with a low thermal stability. Herein, a Mg-MgF2 nanocomposite is successfully fabricated by reactive milling. The thermal stability is largely enhanced from similar to 100 degrees C for nanocrystalline Mg to similar to 450 degrees C for Mg-MgF2. The bulk Mg-MgF2 nanocomposite consolidated at a high temperature of 500 degrees C under 6 GPa exhibits a high compressive yield strength of 582 MPa. Meanwhile, the MgF2 nanoparticles significantly improve the high-temperature hardness of nanocrystalline Mg. The fine, dispersed and thermally stable MgF2 nanoparticles with a strong interfacial bonding with the matrix are the microstructural features that dominate the superior properties - high thermal stability and high strength at room and elevated temperatures. (C) 2017 Elsevier B.V. All rights reserved.