Loading...

Characterization of Elecroless Ni-P-Al2O3-SiO2 Nano-composite Coating on Aluminium

Rahemi Ardekani, Saeed | 2015

648 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 47798 (07)
  4. University: Sharif University of Technology
  5. Department: Materials Science and Engineering
  6. Advisor(s): Afshar, Abdollah; Dolati, Abolghasem
  7. Abstract:
  8. In this study Ni-P-Al2O3-SiO2 nano composite coating developed on aluminium alloy 6061 using electroless method. Due to oxidation of aluminium, a double zincate pretreatment performed to obtain proper adhesion of coating on substrate. Effect of solution temperature and heat treatment on thickness and property of nano composite coating was studied. Furthermore, effect of concentration of nano particles in electroless solution on thickness, morphology, micro hardness, wear behavior, corrosion resistance and particle content in coating were investigated. Field emission scanning electron microscopy (FESEM, Hitachi S-4160) with energy dispersive spectroscopy (EDS) was used to evaluate morphology and composition of the coatings. The crystalline structure of coating was assessed by X-ray diffraction (XRD). The result showed that the maximum weight percent of Al2O3 and SiO2 in coating to get on highest microhardness and wear resistance is 3.57 and 2.73, respectively. Polarization curve in 3.5% NaCl showed that current density reduce to 0.11 µA/cm2 due to presence of Al2O3 and SiO2. Furthermore, effect of heat treatment for five temperature studied and showed that the highest hardness was 1373 vickers when we performed heat treatment at 400 ° C for 1h. Moreover, wear bevavior of coating improved after heat treatment and the weight loss was 0.42 mg. By decreament of solution temparature to 75 ° C,the deposition rate and micro hardness reduced to 5.1 µm/h and 503 vickers, respectively
  9. Keywords:
  10. Electroless ; Aluminum ; Nanoparticles ; Wear ; Hardness ; Silica ; Alumina ; Nickel-Phosphorous Coating

 Digital Object List

 Bookmark

No TOC