Mixing metal powders in cold spray is of significant interest not only because it is a straightforward method to produce novel composites, but also it has been observed to generate beneficial effects, e.g. improved deposition efficiency (DE). However, the mechanisms behind DE improvements are still not clear fundamentally. In this paper, two examples of mixing metal powders effects in cold spray are introduced: 1) the first example focuses on the effects of different particle/substrate interactions which occurred during cold spray of SS/Fe mixed powders; 2) the second example presents the DE-improving effect of depositing mixed metal powders onto polymers. Various mechanisms associated with the cold spray deposition characteristics of mixed metal powders are discussed in this paper.

Selective Laser Melting (SLM) involves numerous fabrication parameters, the interaction between those parameters determine the final characteristics of the resulting part and because of the latter, it is considered a complex process. Low-density components is one of the main issues of the SLM process, due to the incorrect selection of process parameters. These defects are undesired in high specialized applications (i.e. aerospace, aeronautic and medical industries). Therefore, the characterization of the defects (pores) found in aluminum parts manufacture by SLM and the relationship with fabrication parameters was performed. A robust orthogonal design of experiments was implemented to determine process parameters, and then parts were manufactured in SLM. Relative density of the samples was then characterized using the Archimedes principle and microscopy; the data was then statistically analyzed in order to determine the optimal process parameters. The main purpose of the present research was to establish the best processing parameters of an in-house SLM system, as well as to characterize the pore geometry in order to fully eliminate pores in a future research.

Considering their distinctive properties, titanium alloys are used in foremost industries, including the aeronautic, automotive and biomedical industries. The reduced machinability of titanium alloys is due to their low thermal conductivity and high plasticity behavior. In the biomedical sector, one of the most studied alloys is Ti-6Al-4V. In the case of the Ti-6Al-7Nb alloy, scarce investigations are identified, related to machinability studies. The machining of Ti-6Al-7Nb alloy requires the development of new tools with higher properties, which provide better performance. The objective of this study is to present the experimental results related to a novel ceramic cutting tool, in terms of cutting tool life and productivity, in the machining of Ti-6Al-7Nb alloy. A turning operation of a 25 mm diameter bar was performed; the cutting speed was varied in three levels. The results showed the high performance of this type of tools, from the point of view of machinability. The values of the obtained cutting forces are found in the ranges reported by the consulted literature using ceramic tools. The surface roughness values were considered appropriate, taking into account that the tool is recommended for roughing and semi-finishing operations. The most relevant results were obtained in terms of productivity, considering that the performance is 2.53 times higher than the presented in similar works.

Even though AA 7075 is an aluminum alloy with high mechanical properties, it is not often applied in manufacturing. This is so, because it is considered as very difficult to produce defect free welded joints. This is so, because this alloy has a tendency to hot cracking. The metallurgical problems that appear during welding of AA 7075 have not been fully solved but they have been reduced by applying alloys such as: 4043 and 5356 as filler metals. However, in literature there is little information about the metallurgical effects of these types of filler metals applied in arc welded joints of AA7075. This is especially true for Tungsten Inert gas welding. Therefore, this work is focused in comparing the microstructure and Vickers microhardness in weldments of AA 7075 with ER4043, ER5356 and AA7075 as filler metals. Besides, a set of welded joints with the three different filler metals were quenched after welding in order to modify the final microstructure. The results were evaluated by microstructural analysis focused on the Heat Affected Zone and Vickers microhardness and they were compared among them.

The present work aims to explore the tribological behavior of the laser texturing process with different patterns on a Co based alloy using a pulsed Nd: YAG laser. Different parameters such as peak power, speed and spot diameter of the laser were explored for the experimental setting. The microstructural analysis was performed using scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and nanoindentation tests. The influence of the different textured patterns of the tribological performance tested with a pin-on-disc tribometer under lubricated sliding condition was evaluated. The results showed that typical interdendritic structures in the as-cast CoCr alloy condition were refined due to the heat input and fast cooling rate during the laser treatment. The refined microstructure showed less volumetric loss resulting in a increment of wear resistance and a better tribological performance than as-cast alloy. The correlation among laser parameters, microstructural effect and their influence in wear resistance is discussed.

Nowadays the different industries is searching continuous improvements in the welding processes of the components of its products, in order to avoid the disadvantages obtained in the past by joining their parts through conventional fusion welding processes, affecting their microstructural development and consequently decreasing the principal mechanical properties. The friction-stir welding process is a solid state technique which does not reach the melting point of the material, promoting the plasticization of the metal by controlling its microstructure and mechanical behavior. However, the after mentioned advantages are the result of an adequate control of the process parameters, so that the aim of the present investigation is to study the microstructural and mechanical development of 5052-H32 butt joints welded by FSW process using a high wear resistance tool (PCBN tool) as well as the mechanical behavior suffered.

Hybrid welding is a process used in aeronautical materials to obtain benefits such as complete penetration, narrow heat affected zones, reduce filler material used, among others, mainly due the ability of the process to control filler-metal additions and heat input in materials such as steels, titanium and aluminum alloys. Recently a new industrial revolution is taken place called manufacturing 4.0, the aeronautical and automotive industry have a great interest in all the pillars which making it up, one of the principal pillars is the big data analysis such as welding parameters applied in advances welding processes. The present work describes a welding optimization applying non-dominated sorting genetic algorithm-III (NSGA-III) to find and predict depth penetration (DP) and mechanical properties, specifically ultimate tensile strength (UTS) in ASTM 1520 steel welded by a hybrid laser arc welding with the objective to improve the weld quality. A diverse experiment were used in order to obtain a suitable model, considering welding speed (WS), wire feed rate (WF), voltage (V), current (A) and laser power (P). The experimental results demonstrated that the pareto front values obtained by NSGA-III improve the DP and UTS. Microstructural phases and mechanical properties were discuss to complement the values obtained and chosen.

In this work, the evaluation of the growth of cracks in specimens of square cross section requested by symmetrical cyclic torsion moments was performed. The specimens were manufactured from AISI 1015. A pre-crack was machined on one side to induce the crack growth. The crack length with the increase in the number of cycles was measured by means of penetrating liquids method. By means of the Finite Element Method, the stress – strain state of the specimens was simulated. The displacements in the crack tip were determined to apply the technique of the Crack Tip Opening Displacements to calculate the Stress Intensity Factor. The calculated Stress Intensity Factor was related to the dimensions of the specimen and the size of the crack to propose an equation for the shape function.

The doped iron arsenides present outstanding properties, one of them is an unconventional superconductivity, an unusual coexistence of superconductivity and magnetism. We calculated the electronic structure of the pure and Ni-doped BaF e2As2 by the embedded cluster method at the electron correlation level; the latter is calculated through the second- order Møller Plesset perturbation theory. For the doped clusters, we calculated the relaxation of the first and second neighbors of the impurity by optimizing their positions in the cluster. The total electronic density is analyzed through natural bond orbitals and the population of each atomic orbital (basis function) is determined; the robustness of this determination is tested comparing results obtained for the unrelaxed and relaxed cluster. The orbital population analysis uncovers some properties of magnetism and superconductivity in BaFe2As2. From our results, linear elasticity allows us to estimate the relaxation volume of Ni impurity.