Improving Tribological Behavior of Porous Anodic Film by Electrophoretic Impregnation by a Tio2 Synthesized Nanoparticle

This chapter deals with the study of the elaboration of a stable suspension of TiO2 nanoparticles and their incorporation by electrophoretic deposition into pores of anodized 5754 aluminum alloy. The as-synthesized TiO2 nanopowder was characterized by X-ray diffraction, scanning and transmission electron microscopy (TEM), and infrared spectroscopy. During this work, transmission electronic microscopy (TEM) analysis showed that the resulting particles had a narrow size distribution with crystallite size of about 15 nm. The zeta potential and stability of TiO2 nanoparticles dispersed with poly(acrylic acid) (PAA) in aqueous solution were also measured. Porous anodic film was elaborated in phosphoric acid electrolyte and then filled by TiO2 particles using electrophoresis method. Furthermore, the effect of PAA content and pH on the suspension stability has been investigated. It was also demonstrated that buffered suspension by adding glycine avoids gelating phenomena which inhibits the insertion of nanoparticles inside the pores of anodic film. It was noted also that the electric field already applied greatly influences the electrophoretic deposition process (EPD). FEG-SEM observations showed that larger (125 nm diameter) and linear pores of 6 μm in length are successfully filled in 5 min. Finally, the composite anodic film tribological behavior was studied and the obtained results revealed that the insertion of the TiO2 nanoparticles into the pores of the anodic film improves its tribological properties.