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AZ91D/TiB 2 Nanocomposites Fabricated by Solidification Nanoprocessing
Author(s) -
Choi Hongseok,
Sun Yi,
Slater Ben P.,
Konishi Hiromi,
Li Xiaochun
Publication year - 2012
Publication title -
advanced engineering materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.938
H-Index - 114
eISSN - 1527-2648
pISSN - 1438-1656
DOI - 10.1002/adem.201100313
Subject(s) - materials science , intermetallic , ultimate tensile strength , microstructure , nanocomposite , nanoparticle , composite material , ductility (earth science) , casting , grain size , brittleness , metallurgy , nanotechnology , alloy , creep
AZ91D, as one of the most widely used casting magnesium alloys, still suffers from inadequate mechanical performances for various applications. Nanoparticles could be used to form high‐performance magnesium matrix nanocomposites. Among all nanoparticles, TiB 2 has great potentials to enhance the mechanical property of AZ91D. This paper studies the microstructures and mechanical property of AZ91D‐TiB 2 nanocomposites fabricated through solidification nanoprocessing. TiB 2 nanoparticles with a diameter of 25 nm are effectively fed into the AZ91D melt through a newly developed automatic nanoparticle‐feeding system. Ultrasonic cavitation is used to disperse these nanoparticles in AZ91D melt for casting. With 2.7 wt% (about 1.0 vol%) of TiB 2 nanoparticles addition, the mechanical property of AZ91D is much enhanced (by 21, 16, and 48% for yield strength, tensile strength, and ductility, respectively). Microstructural analysis with optical microscope, SEM, and S/TEM show that α‐Mg grain and a network of massive brittle intermetallic phase (β‐Mg 17 Al 12 ) are simultaneously refined and modified. Further study suggests that the enhancement of mechanical properties of AZ91D is attributed not only to primary phase grain refinement, but also to the modification of intermetallic β‐Mg 17 Al 12 by TiB 2 nanoparticles.