%0 Journal Article
%T Si3N4 Nanoparticle Addition to Concentrated Magnesium Alloy AZ81: Enhanced Tensile Ductility and Compressive Strength
%A Muralidharan Paramsothy
%A Xing He Tan
%A Jimmy Chan
%A Richard Kwok
%A Manoj Gupta
%J ISRN Nanomaterials
%D 2012
%R 10.5402/2012/169850
%X This study is aimed at understanding the tensile ductility and compressive strength-enhancing dual function of nanoparticles in a concentrated magnesium alloy (AZ81) nanocomposite. Si3N4 nanoparticles were selected for reinforcement purposes due to the known affinity between magnesium and nitrogen. AZ81 magnesium alloy was reinforced with Si3N4 nanoparticles using solidification processing followed by hot extrusion. The nanocomposite exhibited similar grain size and hardness to the monolithic alloy, reasonable nanoparticle distribution, and nondominant (0 0 0 2) texture in the longitudinal direction. Compared to the monolithic alloy in tension, the nanocomposite exhibited higher failure strain (+23%) without significant compromise in strength, and higher energy absorbed until fracture (EA) (+27%). Compared to the monolithic alloy in compression, the nanocomposite exhibited similar failure strain (+3%) with significant increase in strength (up to +20%) and higher EA (+24%). The beneficial effects of Si3N4 nanoparticle addition on tensile ductility and compressive strength dual enhancement of AZ81 alloy are discussed in this paper. 1. Introduction Silicon nitride nanoparticles in the shape of near-spheres and wires have been synthesized by chemical vapor deposition (CVD) [1, 2]. In the case of nanowires, the catalytic properties of metal nanoparticles were utilized during CVD to promote the directed silicon nitride growth at nanoscale [2]. On one hand, nanoparticles are active towards cells (or bioactive), where the specific biological function at cellular level can be disrupted, modified (negatively or positively), or promoted by the uncoated nanoparticles present [3]. On the other hand, silicon nitride nanoparticles have been coated and chemically stabilized prior to effective dispersion in a rubber matrix [4]. In the context of mechanical (crystallographic structure related) or functional (electronic structure related) properties, the function of nanoparticles in a metallic matrix is related to (a) nanoparticle-matrix reactivity and (b) nanoparticle distribution in the matrix. Magnesium alloys are an easily available lightweight and energy saving metallic matrix. In particular, the AZ (Aluminium-Zinc) series of magnesium alloys are characterized by (a) low cost, (b) ease of handling, (c) good strength and ductility, and (d) resistance to atmospheric corrosion [5]. These qualities enable the common use of AZ series magnesium alloys [5]. Regarding magnesium nanocomposites, the friction stir processing technique has been used to add SiO2 nanoparticles to
%U http://www.hindawi.com/journals/isrn.nanomaterials/2012/169850/