Evaluation of Coating Ability of TiO2 Nanoparticles Onto Aluminum Alloy Sheet by Physicochemical Analysis

TiO₂ nanoparticle films were successively coated onto aluminum (Al) alloy sheet using a coating technique at 150°C for 5 h. This was a chemical sintering method, integrated with Al/TiO₂/Al sandwich coupling and used weak acid as a binder. To evaluate the coating ability of the TiO₂ nanoparticles on the aluminum alloy sheet, the physicochemical characteristics of the film samples were analyzed by means of SEM-EDS, FT-IR and XRD. The TiO₂ films prepared by the coating technique at 150°C for 5 h were compared with TiO₂ films prepared by the doctor-blade technique at 500°C for 10 min using two different organics as binders. The results of the physicochemical analysis indicated that the coating technique at 150°C for 5 h provided superior coating ability of TiO₂ nanoparticles onto aluminum alloy sheet than the doctor-blade technique. This may have been because of reduction of the thermal gradient at the TiO₂ interface, which affected the relaxation of internal and external stresses on the TiO₂ film on the aluminum alloy substrate. In this work, the TiO₂ film prepared by chemical sintering method, integrated with Al/TiO₂/Al sandwich coupling at 150°C for 5 h using weak acid mixed with 5 wt.% ammonia as a binder proved to produce the optimum TiO₂ film; however, film thickness control using the coating technique at 150°C for 5 h still needs to be developed.

Keywords: aluminum; chemical sintering; wet coating; doctor-blade; thin film; titanium dioxide

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