Moises Meza Pariona

By Moisés Meza Pariona and Viviane Teleginski

Part of the book: Convection and Conduction Heat Transfer

By Moisés Meza Pariona

Part of the book: Developments in Corrosion Protection

By Moises Meza Pariona and Katieli Tives Micene

An analysis was made of microstructure of hypereutectic Al-2.0 wt.% Fe alloy treated by laser surface remelting (LSR), microhardness test, and electrochemical behavior test and their numerical simulation was done. Microstructure was analyzed by optical microscopy, field-emission scanning electron microscopy and Vickers microhardness tests. Results obtained in this study indicate in LSR-treatment occurred rapid heating and followed by rapid cooling, resulting in formation of a thin recast layer with a refined microstructure, with dissolution of precipitates and inclusions and formation of metastable phases, however, an overlapping line on consecutive weld fillets was observed. Furthermore, analysis of Vickers hardness were done in the cross-sectional area of treated sample and on the treated sample surface, therefore, result a greater microhardness of the treated region than untreated substrate. Through the electrochemical impedance spectroscopy (EIS) test, laser surface remelting-treated workpiece exhibit higher polarization resistance than untreated, at 11 times higher and capacitive behavior of material is related to aluminum oxide layer properties, then, microstructure characteristic caused by overlapping ratio and multi-track has a strong effect on electrochemical process.

Part of the book: Aerospace Engineering

By Moises Meza Pariona

In this work, a numerical simulation by finite element method (FEM) and optimized multigrid technology was applied. In order to study the influence of multi-track overlapping on the microstructure processed by laser surface remelting (LSR) and so, the validation of the experimental and the numerical simulation results of the multi-track overlapping were accomplished, which was the goal. It was verified in this work, multi-track overlapping and thermal cycling allied to high-speed cooling of liquid metalinfluence the liquid flow, mechanism of heat transport, and microstructure evolution in the molten pool of laser-treated alloy, promoting so a nanostructure characteristic. Thus, FEM is capable of accurately simulating the multi-track overlapping of the workpiece LSR-treated. Results of the overlapping ratio, as well as, the depth where the phase transformation occurs from liquid to solid was very nearby, therefore, simulation and experimental results agree quite well. This type of laser-treated alloy has very special characteristics and it is of innovative character, then, in aerospace, aeronautical, and automobile industries can be applied.

Part of the book: Heat Transfer