https://popups.uliege.be/esaform21/index.php?id=3384 Publications of Auteurs Antonio Formisano fr 0 https://popups.uliege.be/esaform21/index.php?id=4131 Niobium is a ductile transition metal of growing interest for several technological applications, thanks to its intriguing characteristics, among them high melting point, moderate density, good ductility, high corrosion resistance and superconductivity. By contrast, its use is limited by some weaknesses lied to the mechanical properties, which can undermine the quality of the surfaces worked by metal forming processes. Sheets of pure Niobium can be used for the manufacture of extremely customized components and a flexible process like the incremental sheet forming fits well with this manufacturing philosophy; in fact, this technique does not require complicated tools and/or dedicated equipment and is capable to respond quickly to the market demands. The scope of this paper is to investigate the influence of the tool/sheet contact conditions on different features like the forming loads, the surface quality and the occurrence of failures, when pure Niobium rolled sheets are formed incrementally. To this aim, the simplest variant of incremental sheet forming, namely single point incremental forming, was considered by using a common fixed end forming tool with hemispherical head. The process was carried out under dry and lubricated tool/sheet contact conditions, following the indications from a preliminary campaign of wear tests conducted by a pin-on-disk apparatus. The experimental campaign highlights the strong influence of the tool/sheet contact conditions and the importance of a correct choice of them on the features investigated, in order to limit the forming forces and the risk of failure, as well as to preserve the surface quality of the components made by incremental sheet forming of Niobium. Wed, 31 Mar 2021 09:09:19 +0200 Wed, 31 Mar 2021 09:09:19 +0200 https://popups.uliege.be/esaform21/index.php?id=4131 https://popups.uliege.be/esaform21/index.php?id=4036 Metal foams have a number of established niche market and potential applications under investigation due to their peculiarities including thermal, acoustic and mechanical properties at low weight. In order to produce structures resistant at high temperature and acting as barrier to the fire, metals with closed cells are often required, and one of the most consolidate manufacturing process for their production is the gas releasing particles decomposition in semisolids, by means of which a foam is created by a foaming agent dispersed into a precursor. In previous researches, the authors have investigated the possibility of foaming the aluminum starting by a precursor, placed between two skins consisting of steel grids, in order to obtain a sandwich structure at the same time of the foaming step. In line to continue on this topic and to improve the compression strength of the aluminum-foamed core, in this work the steel grid was used both as skins and as a corrugated skeleton inside the core. Different types of sandwich structures were manufactured, following some experimental tests executed to determine the optimal value of temperature and time to foam the precursor. Then, compression tests were carried out, in order to investigate the effectiveness of the proposed solution on the improvement of this mechanical behavior. The mechanical tests highlighted the increase of mechanical properties using this type of corrugated core. Tue, 30 Mar 2021 10:35:30 +0200 Tue, 30 Mar 2021 10:43:32 +0200 https://popups.uliege.be/esaform21/index.php?id=4036