Development and Characterization of Zn-Al2O3 Composite

Abstract

Nanocomposites have been of great importance lately due to the wide range of possibilities of developing materials with required tailored physical, mechanical and electronic properties at low cost having diverse applications ranging from coating applications and electronic or optic devices to structural components, automotive and industrial applications and numerous others. By optimizing and controlling the fabrication process, the mechanical properties like toughness, hardness, wear and abrasion resistance, flexural strength as well as thermal and electrical properties of materials can be enhanced that can have wide range of applications. The present study reports with the fabrication of Zn-Al2O3 composites by powder metallurgy route and their various physical and mechanical properties. Zinc (Zn) and alumina (Al2O3) powders were blended together in proper volumetric ratio and subsequently compacted in a uniaxial cold compaction machine under a load of at 300 MPa. The green compacts were later sintered at 500∘C for a period of 2h in Ar atmosphere. The Zn-10, 20, 30, 50 and 60 vol. % Al2O3 composites developed were analyzed by optical microscopy, x-ray diffraction (XRD), scanning electron microscopy (SEM) and differential scanning calorimetry/thermogravimetric analysis (DSC/TGA). Mechanical properties of the various composites like hardness and wear resistance were also determined. The hardness of the Zn-Al2O3 composites showed a gradual increase with the increase in Al2O3 content. The wear resistance of the Zn-Al2O3 composites showed an improvement upto the addition of 30 vol. % Al2O3 beyond which there was a deterioration in the wear resistance of the composites. The relative density of the composites also show a gradual increase with the increase in Al2O3 content and it is found around 81.6% in the case of Zn- 60 vol. % Al2O3 composite.