**5. Conclusions**

It was expected that a coating presenting a well-dispersed second phase and a high amount of micrometric γ-Al2O3 particles presented the best anticorrosive performance. However, these effects had no direct influence on the corrosion performance of these coatings in 0.5 mol L-1 NaCl, and no significant differences could be noted among their Ecorr, as shown in Table 5 and Figure 9, whereas the jcorr values increased when the applied potential became more negative. Moreover, the anticorrosive performance of these coatings, in terms of jcorr, was worse than the values obtained for the pure copper coating (5.27 μA cm-2). The thin layers produced under the deposition conditions could have probably masked the effects of the deposition parameters on the anticorrosive performance of these coatings. In addition, the micrometric size of the γ-Al2O3 particles could have contributed to create defects and voids in the coatings, enhancing the corrosion process, confirming the results earlier shown for Cu-μSiO2 coatings [91], and showing that the size of the particle is an important parameter to produce composite coatings

> 1 -1.20 10.3 -0.411 2 -1.50 62.2 -0.423

**Table 6.** and Ecorr values of composite coatings Cu/γ-Al2O3 in 0.5 mol L-1 NaCl. The coatings were produced at -1.20

**Figure 9.** Polarization curves of Cu/γ-Al2O3 coatings/steel substrate systems in 0.5 mol L-1 NaCl.

Cu/boehmite nanocomposite coatings [AlO(OH) Disperal P2, 25 nm size; Sasol®] was produced onto steel substrate (AISI 1020) by DC electrodeposition using j = 7.0 and 21.0 A

**(VSSE) jcorr (μA cm-2) Ecorr (VSCE)**

with high anticorrosive characteristics.

176 Electrodeposition of Composite Materials

**Experiments Applied cathodic potencial**

and -1.50 VSSE after previous stirring for 5 h of at 800 rpm [61].

It is possible to conclude that, although composite coatings have been under investigation for many years, their application as anticorrosive coatings still needs more research. The effects of the electrical nature of the particle and the bath composition (e.g., complexant, additives, and surfactants) on the anticorrosive characteristics of the MMC coatings must be studied. Other parameters, such as stirring speed, previous stirring time, and solution temperature, must also be optimized to enhance the incorporation of the nanoparticles to the coatings and relate this effect to their anticorrosive properties. In addition, the corrosion processes in different electrolytic media must be evaluated and be related with the deposition parameters. Therefore, there is a great research opportunity involving the production of MMC coatings by electrodeposition and their characterization as anticorrosive coatings.
