Application of ball milling in the synthesis of AA 7075-ZrO2 metal matrix nanocomposite

Ball milling was used to reduce the particle size of yttria-stabilized ZrO2 powders with the aim of introducing it into the AA 7075 matrix. It was observed that during the mechanical milling of the ZrO2 powders a destabilization of the tetragonal structure occurred, which was confirmed by the X-ray diffraction results. A transition from tetragonal to monoclinic structure resulted as a consequence of the application of ball milling. The synthesis of the composite was carried out in the same way by applying mechanical ball milling in order to disperse 2 and 5wt.%25 of zirconium oxide particles into the Al alloy matrix. It was found that longer times were needed for the 5wt.%25 of ZrO2 to achieve a complete dispersion into the matrix, unlike 2wt.%25 of ZrO2 sample, being 15 and 10h, respectively. It was evident that the presence of ZrO2 particles had a marked influence upon the powder morphology and particle size of the matrix during the milling process. Despite the structural change observed, a relatively good homogenous dispersion of ZrO2 particles was found after ball milling. © 2015 Elsevier B.V.

Al composites; Mechanical milling; Powder characterization Aluminum alloys; Dispersions; Mechanical alloying; Metallic matrix composites; Milling (machining); Nanocomposites; Particle size; Powder metals; X ray diffraction; X ray powder diffraction; Yttrium oxide; Zirconia; Al composites; Homogenous dispersions; Mechanical ball milling; Mechanical milling; Metal matrix nano composites; Monoclinic structures; Powder characterization; Tetragonal structure; Ball milling; nanocomposite; yttrium; zirconium oxide; Article; ball milling; chemical procedures; chemical structure; dispersion; morphology; particle size; powder; synthesis; X ray diffraction

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