**2. Superficially treated 2024 aluminum alloy technology**

The method of oxidization by micro arcs is an electrochemical surface treatment; it is similar to the anodization, where we use a very high voltage in order to produce electric discharges. It is a chemical conversion of the substrate by its oxide, therefore an excellent adhesion. The oxide layer is formed by applying an electric potential (at least 200 V), whereas the piece is immersed in an acid electrolyte. Discharges are produced, agglomerate, and make the oxide dense and partially converted to amorphous alumina in crystal form such as the cordon. The structure of coatings applied by the micro-arc oxidation method to DI6 aluminum alloy) was investigated with the use of scanning electron microscopy and chemical and X-ray diffraction analyses. It was found that the coating is inhomogeneous. Its structure and composition change across the thickness and the micro inhomogeneity observed in analyzing the microstructure of a transverse micro-sample and confirmed by the data of coating microhardness measurements are characterized by the formation of a honeycomb type structure. Consequently, the coating may be considered as a composition material with uniformly distributed hard islands surrounded by softer veins. **Tables 1** and **2** shown chemical composition and mechanical characteristics of aluminum alloy 2024 [5].


**Table 1.**

*Chemical composition of the superficially treated alloy.*

*Mechanical Resistance of a Superficially Treated Alloy Drill Pipe during Onshore Drilling DOI: http://dx.doi.org/10.5772/intechopen.101867*


**Table 2.**

*Results of tensile testing (micro-tests) on test-tubes in the superficially treated alloy, carried out on the machine "ALA-TOO".*
