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Treballs Finals de Grau d'Enginyeria Química, Facultat de Química, Universitat de Barcelona, Curs: 2015-2016, Tutores: Irene Garcia Cano i Núria Cinca Luis, Commercial titanium alloys, which are used in automotive and aerospace applications, are characterized by a low specific weight, high strength and an excellent corrosion resistance at relatively low temperatures. In some applications, they are exposed to a combination of high temperatures and mechanical loading as well as wear damage. However, the oxidation and abrasive resistance of titanium at high temperatures are rather poor; alloys such as Ti6Al4V have applications which are limited to temperatures below 500ºC; therefore it is of interest to increase their application temperatures. Several methods have been employed to increase the oxidation resistance to 900ºC. Among them, the use of titanium aluminide coatings has been considered of interest, especially the titanium trialuminide, which possesses enough aluminium content to form protective alumina layers. Some approaches to this strategy have included the use of conventional thermal spray technologies. In the present work, we proposed the use of the Cold Gas Spray (CGS) process to first try to form γ-TiAl coatings on Ti6Al4V substrates. Due to some handicaps given by the low deformability of such powder alloy, γ-TiAl+Al composite coatings were produced and annealed afterwards to form the TiAl3. These coatings have been characterized from the microstructural point of view as well as their wear resistance and oxidation performance

Treballs Finals de Grau de Química, Facultat de Química, Universitat de Barcelona, Any: 2016, Tutors: Carlos M. Müller Jevenois i Núria Cinca Luis, Titanium is a metallic material that has been studied for decades because of its interesting chemical, physical and biological features. More specifically, there have been numerous efforts in studying how the formation of ordered titanium oxide (TiO2) structures on its surface affects its properties (optical, catalytic, electrical, biocompatibility...). These structures can be obtained by several techniques, such as from anodization. This electrochemical technique allows obtaining a controlled oxide layer with the desired thickness and structure, and if certain parameters are well defined (electrolyte, potential applied, time...), ordered nanostructures. This range of structures can be obtained using a power supply controlled by a computer and a simple experimental system. The aim of this project is the electrochemical production of titanium oxide nanotubes and its characterization, as well as creating a hierarchical structure (macromicronano) to see which impact has the roughness of the substrate in the bioactivity and biocompatibility of this material.