Loading...

Investigation Ni-P-Al2O3-SiO2 Nano Composite Coating on Aluminum by Electroless

Ghanbari, Amir Ali | 2015

488 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 50576 (56)
  4. University: Sharif University of Technology, International Campus, Kish Island
  5. Department: Science and Engineering
  6. Advisor(s): Afshar, Abdollah
  7. Abstract:
  8. Electroless coating is a chemical reduction process which depends on the catalytic reduction. In this study, the influences of different concentrations, stirring rate, pH and heat treatment of Al2O3 and SiO2 Nano sized particles in the bath on deposition rate, hardness, wear resistant, surface morphology and corrosion behavior of the Ni-P-Al2O3-SiO2 composite coatings have been investigated. The microstructure was investigated by field emission scanning electron microscopy (FESEM) and among the nanoparticles SiO2 and Al2O3 have drawn attention due to their high hardness, availability, particles distribution and reduced cost. The amount of Al2O3 and SiO2 was examined by Energy Dispersive Analysis of X-Ray (EDS). Increase of SiO2 and Al2O3 nanoparticles in the bath up to 2.5 gr/l, caused the spectroscopy of coating particles to reached to 4.5 wt% which is the highest amount of nanoparticles in the coating. The hardness of the Ni-P-Al2O3-SiO2 coating increased from 361 HV in equal SiO2-Al2O3 nanoparticles to 992 HV after heat treatment at 400 °C for 60 min and and wear resistant decrease from 5mgr to 1.8 m gr respectively. Corrosion behavior of coated aluminum was evaluated by polarization techniques. The results illustrated that the corrosion rate would be decreased 6.7–1.25 µA/cm^2 and the corrosion potential would be increased −0.68 to −0.5 V with increasing the quantity of the Al2O3 and SiO2 nanoparticles in the bath
  9. Keywords:
  10. Corrosion ; Hardness ; Electroless ; Wear Resistance ; Nano Sized ; Al-5vol%Al2O3 Nanocomposite (Al2o3) ; Nano-Composite Coating

 Digital Object List

 Bookmark

No TOC