Fabrication and mechanical properties of mesoporous silica nanoparticles reinforced magnesium matrix composite

This study investigated, for the first time, the influences of mesoporous silica nanoparticle (MSN) in the magnesium (Mg) matrix on the mechanical properties. Sintered compacts of Mg-xMSN composites (x = 2, 4, 6, 8, 10 wt%) and pureMg were fabricated by spark plasma sintering (SPS) after high-energy wet ball milling. Milled powders and sintered samples were characterized by XRD, SEM, TEM, hardness tester, and universal testing machine. Results revealed that ball milling significantly reduced the particle size of Mg. Densities of all the sintered samples were within 1.899 +/- 0.003 g/cm(3). Nanocrystallines were found in the sintered compacts. Mg-8wt% MSN exhibited the highest compressive strength of 414 +/- 7.50 MPa, the highest bending strength of 210 +/- 14.38 MPa, and the highest specific compressive strength of 217.88 N m/kg. These results indicated the invention of a new Mg-matrix composite with low density and high strength, for which the addition of MSN and the formation of rigid Mg2Si phase were mainly responsible. (C) 2017 Elsevier B.V. All rights reserved.