High-entropy alloys (HEAs) have been around since 2004. The breakthroughs in this field led to several potential applications of these alloys as refractory, structural, functional, and biomedical materials. In this work, a short overview on the concept of high-entropy alloys is provided, as well as the theoretical design approach. The special focus of this review concerns one novel class of these alloys: biomedical high-entropy alloys. Here, a literature review on the potential high-entropy alloys for biomedical applications is presented. The characteristics that are required for these alloys to be used in biomedical-oriented applications, namely their mechanical and biocompatibility properties, are discussed and compared to commercially available Ti6Al4V. Different processing routes are also discussed.

Inserted in the scenario of innovations and technological trends of Industry 4.0, this work aims to obtain detailed knowledge on the influence of idle time between layers as thermal control technique for the Wire Arc Additive Manufacturing (WAAM) with two GMAW process variants of high controllability (CMT and CMT Pulse). The problem focuses on the deposition of thick walls, seeking to emulate the challenges of manufacturing big parts with medium geometric complexity, such as propellers and screws, which usually have sections of this thickness. Although works in the area of additive manufacturing point out the use of idle time as a feature to stabilize the thermal gradient, detailed information about the thermal behavior ends up being omitted. Both processes variants used presented high metallic transference stability and low thermal input when compared to the conventional GMAW, being positive differentials for WAAM. In the tests, walls with eight layers were built with ER309LSi steel in which the interlayer idle time varied from 0 to 300 s. It can be concluded that both processes are WAAM compliant, and that although the CMT Pulse has a higher energy input, the temperature control by idle time was able to control the thermal accumulation in the part for both processes.

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The latest advancements of MIG/MAG welding technologies have experienced a steep evolution in functionality, reliability and ever-growing process and weld controllability, within widely interdisciplinary approaches and driven by demanding trends of Advanced Manufacturing (Industry 4.0). Technologic development can be optimized through basic research, which focuses on understanding the physical phenomena involved in metal transfer, weld pool behavior and bead geometric formation and their correlation with each other and with the process´s variables. In this context, the objective of this work is to compare different waveforms of the short-circuiting MIG / MAG process with current control, namely CCC and SOFT, with the conventional process version, evaluating the influence of the electrical parameters on process stability and the general morphology of the weld beads. Analysis of metal transfer by means of high-speed filming and thermal analysis by infrared thermography supported conventional oscillogaphic monitoring for process characterization. Spatter emission assessment by means of image analysis was performed as well. The process´s versions with current control resulted in better operational weldability, geometric control of the bead and lower spatter emission.