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Titanium and its alloys are widely used in cranioplasty because they are biocompatible with excellent mechanical properties and favor the osseointegration with the bone. However, when Titanium alloys have to be worked several problems occurred from a manufacturing point of view: the standard procedure for obtaining Titanium prostheses is represented by the machining processes, which result time and cost consuming. The aim of this research consist to introduce alternative flexible sheet forming processes, i.e. Super Plastic Forming (SPF) and Single Point Incremental Forming (SPIF), for the manufacturing of patient-oriented titanium prostheses. The research activities have already highlighted the potentiality of the investigated forming processes that can be alternatively used taking into account both the damage morphology and the need of urgency operation. In the present work, the way of manufacturing the Ti prostheses by SPF and SPIF is described. A comparative analysis has been performed, thus highlighting the peculiarities of the investigated processes and the prostheses feasibility

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The present work investigates the Hydro Forming process in warm conditions using a numerical/experimental approach; an Al alloy (AA6061 T6) component is used as case study. Experimental tests were carried out for characterizing the material and setting the numerical model. A preliminary experimental step based on both tensile and formability tests allowed to characterize both the mechanical and deformative characteristics of the material according to temperature, orientation and strain rate. Finite Element simulations using ABAQUS/explicit were carried out changing (according to a simulations plan created using the Design of Experiment approach) the process parameters which mostly affect the HF process in warm conditions: the forming pressure, both the initial and final Blank Holder pressure and the Temperature (oil pressure and Blank Holder pressure were related to the material yielding strength). The contour plots of an ad hoc response parameter (LN), able to take into account both the risk of rupture and the level of deformation, allowed to evaluate the regions where process parameters guarantee the optimal working conditions

Dissimilar metal welding involves the joining of two or more different pure metals or alloys, usually by melting and mixing and often with the addition of filler metal. There are several types of dissimilar metal welds including stainless steel, either as base metal or as filler metals. Dissimilar metal joints have distinctive features because of differences in the chemical composition of base metal and filler material. Their alloying elements will diffuse intensely during welding. The structures near the fusion line are very complex. Despite of great potentiality in aircraft and automotive industries, dissimilar joining of hybrid Al-Ti structures is often challenging because of the unavoidable formation of brittle intermetallic compounds, mixing of molten phases, and significant differences in material properties. In this work, dissimilar 2 mm thickness AA6000 and Ti6Al4V butt joints were produced by shifting an Yb fiber laser beam on the upper surface of the Ti sheet. Neither filler wire nor groove preparation was adopted. Different working conditions and seam shapes were assessed. The welds were characterized in terms of metallurgical and mechanical behaviors.