Comparative Study of microstructural, electrochemical and tribo-mechanical properties of electrodeposited Zn-Al2O3/Cr2O3/SiO2 nanocomposite coatings

3^rd International Conference and Exhibition on Materials Science & Engineering

October 06-08, 2014 Hilton San Antonio Airport, USA

N Malatji and A P I Popoola

Accepted Abstracts: Material Sci Eng

Abstract :

Nano-sized particle incorporation into metal matrix for fabrication of advance surface coatings finds variety of applications in surface protection techniques. Al2O3, Cr2O3 and SiO2 nanoparticles have been codeposited with Zn using electrodeposition process to produce Zn nanocomposite coatings. The fabricated coatings were characterized using Scanning Electron Microscope affixed with Energy Dispersive Spectroscopy and X-ray diffractometer. The mechanical and tribological properties of the coatings were investigated using diamond microhardness indenter and CETR tribo-tester. The results revealed that the incorporated nanoparticles induce grainrefinement and modify preferred crystallographic orientation of Zn matrix. The composite coatings exhibited excellent self-lubricating properties and improved microhardness yield. Electrochemical and thermal stability studies revealed that the composite coating possessed improved corrosion resistance and were thermally stable up to 16 hours of heat treatment at 250°C. Comparative studies indicated that Zn-Al2O3 and SiO2 composite coatings possessed better surface properties while incorporation of Cr2O3 improved mostly the mechanical properties. Therefore, Zn- Al2O3 and SiO2 proved to be better coatings which can find variety of industrial applications where both mechanical and electrochemical properties are required.

Biography :

N Malatji holds a Bachelors Degree in Metallurgical Engineering from Tshwane University of Technology. He is currently doing his masters degree in Metallurgical Engineering from the same institution and his project is based on surface coatings and technology.