In:
Key Engineering Materials, Trans Tech Publications, Ltd., Vol. 656-657 ( 2015-7), p. 74-79
Kurzfassung:
In this study nanoTiO 2 particles were incorporated into the electroless plating solution to prepare Ni-P-TiO 2 composite coating on anodized AA7075 aluminum alloy to improve the wear and stress corrosion cracking resistance of the coated alloy in 3.5%NaCl solution. The anodized AA7075 aluminum alloy was also performed by a boiling water sealing treatment for comparison. The wear and stress corrosion cracking (SCC) characteristics were investigated using a self-designed block-on-ring machine and slow strain rate test. The effect of corrosion was evaluated by electrochemical polarization measurements. The surface morphology, element composition and surface hardness of the coating were analyzed by scanning electron microscopy (SEM), X-ray energy dispersive spectrometry (EDS) and Vicker′s hardness tester. Experimental results indicated that after boiling water sealing treatment the resistance properties of the anodized AA7075 aluminum alloy were further improved. The anodizing treatment of AA7075 aluminum alloy gave a thick film with high porosity. The porous film efficiently improved the cohesion, adhesion and hardness of the electroless Ni-P composite coating. Therefore, the electroless Ni-P composite coating deposited on the anodized AA7075 aluminum alloy offered a superior wear, pitting corrosion and stress corrosion cracking resistance properties than both anodizing and sealing treatment. By comparison with Ni-P and Ni-P-TiO 2 coatings the incorporation of TiO 2 resulted in a more uniform and crack-free surface structure of the composite coating. This is responsible for the higher hardness, better wear, pitting corrosion and stress corrosion cracking resistance of the electroless Ni-P-TiO 2 coating.
Materialart:
Online-Ressource
ISSN:
1662-9795
DOI:
10.4028/www.scientific.net/KEM.656-657
DOI:
10.4028/www.scientific.net/KEM.656-657.74
Sprache:
Unbekannt
Verlag:
Trans Tech Publications, Ltd.
Publikationsdatum:
2015
ZDB Id:
2073306-9
