Strength-plasticity-matched (GNPs+GFs)/Mg–3Zn-0.1Ymagnesium matrix composites with high modulus through liquid-phase dispersion and multistep deformation

Abstract

This paper explores the production of high-modulus 3 wt%(GNPs + GFs) composites through high-energy ultrasonics-assisted semisolid stirring followed by combining multidirectional forging (MDF) and extrusion (EX) techniques. Compared to EX-alloy, the yield strength of the MDF + EX composite material was increased to ∼313 MPa, and the modulus was increased from ∼44 Gpa to ∼56.5 Gpa while retaining a higher plasticity of ∼9 %. The mechanical properties of the composites are significantly improved due to several factors. These include the grain boundary strengthening effect caused by refinement and high recrystallization rate, the Orowan strengthening effect due to dynamically precipitated nano-MgZn2 phases, and the homogeneous dispersion of GNPs and GFs.