title: Development of hierarchical magnesium composites using hybrid microwave sintering.
abstract: In this work, hierarchical magnesium based composites with a micro-architecture comprising reinforcing constituent that is a composite in itself were fabricated using powder metallurgy route including microwave assisted rapid sintering technique and hot extrusion. Different level-I composite particles comprises sub-micron pure aluminum (Al) matrix containing Al2O3 particles of different length scale (from micrometer to nanometer size). Microstructural characterization of the hierarchical composites revealed reasonably uniform distribution of level-I composite particles and significant grain refinement compared to monolithic Mg. Hierarchical composite configurations exhibited different mechanical performance as a function of Al2O3 length scale. Among the different hierarchical formulations synthesized, the hierarchical configuration with level-I composition comprising Al and nano-Al2O3 (0.05 microm) exhibited the highest improvement in tensile yield strength (0.2% YS), ultimate tensile strength (UTS), tensile failure strain (FS), compressive yield strength (0.2% CYS) and ultimate compressive strength (UCS) (+96%, +80%, +42%, +80%, and +83%) as compared to monolithic Mg. An attempt has been made in the present study to correlate the effect of different length scales of Al2O3 particulates on the microstructural and mechanical response of magnesium.
authors.affiliation: Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, 117576 Singapore.
authors.forename: Meisam Kouhi
authors.initials: MK
authors.lastname: Habibi
authors.affiliation: Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, 117576 Singapore.
authors.forename: Shailendra P
authors.initials: SP
authors.lastname: Joshi
authors.affiliation: Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, 117576 Singapore.
authors.forename: Manoj
authors.initials: M
authors.lastname: Gupta
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry / Q000528:radiation effects; D019245:Compressive Strength / Q000528:radiation effects; D006361:Heating / Q000379:methods*; D008274:Magnesium / Q000737:chemistry* / Q000528:radiation effects*; D008422:Materials Testing; D008872:Microwaves; D053758:Nanoparticles / Q000737:chemistry* / Q000528:radiation effects*; D013718:Tensile Strength / Q000528:radiation effects
chemical_list: D008274:Magnesium; D000537:Aluminum Oxide