Wear and Corrosion Resistance of Electroless Ni-P- ZnO -SiO_2 Nanocomposite Coatings on Magnesium AZ91D Alloy

摘要

In this work, wear and corrosion behavior of the electroless Ni-P- ZnO-SiO_2 of nanocomposite coatings with concentrations as follows (0.5-0.5),(1-1),(1.5-1.5),( 2-2) g/L were developed on AZ91D magnesium alloy. Surface morphology and elemental analysis were carried out by Optical microscope (OM) and scanning electron microscopy (SEM) coupled with Energy-dispersive X-ray spectroscopy (EDAX). Wear and corrosion resistance were determined by pin-on-disc apparatus, and salts spray method. SEM was used to study wear mechanisms of coated magnesium alloy. The low specific wear rate of 1.3964xl0~5mm~3/Nm of ZnO-SiO_2 was at (1.5-1.5)g/L which showed a better wear resistance to other nano-coated samples follows. The corrosion rate at (1.5-1.5)g/L showed a lower rate of 0.000265 MPY compared to other nano co-deposits. The co-deposits ZnO-SiO_2 with optimum concentration ZnO-SiO_2 at (1.5-1.5)g/L can be for nickel-phosphorus matrix composite nanocoatings for enhanced wear and corrosion resistance.