Metal foils attract a large field of applications, e.g. in micro-technology they are being used for sensors, actors, micro-electro-mechanical systems and in medical devices. Conventional sheet metal forming processes are in principle applicable for metal foil forming. Reducing the sheet thickness to the order of micrometers, however, causes various scaling effects. Therefore, the know-how of co...

A new ohmic contact scheme for gallium nitride is presented. The use of Nitrideforming metal Over Gallide-forming metal, “NOG”, can modify the thermodynamic activity of N and Ga near the interface. This in turn can modify the near-surface point defect concentrations, particularly the vacancies of Ga and N. The principle of this contact scheme was shown to be consistent with results from Ni/Au, ...

Due to the large size and complicated features, brake discs of high-speed trains are difficult forge, so a reasonable design process die parameter prerequisites for successful forming. The flow stress 23CrNiMoV, forged-steel disc material trains, was investigated by uniaxial compression experiment on Gleeble 1500 test machine. Based obtained flow-stress data, series numerical simulation analyse...

For ̄ exible manufacture of a doubly curved sheet metal, a new sheet metal forming process is proposed that uses a movable punch set composed of two pairs of lower support punches and one upper centre punch. The process is characterized by ̄ exibility compared with the existing conventional processes because it does not require any complex-shaped die and the loss of material is minimized by unc...

1 2 2 2 3 3 Thomas Pressel, Anas Bouguecha, Matthias Kammler, Bernd-Arno Behrens, Ute Vogt, Andrea Meyer-Lindenberg, 1 Henning Windhagen 1 Department of Orthopaedic Surgery, Hannover Medical School, Hannover, Germany; E-Mail: [email protected], 2 Institute of Metal Forming and Metal Forming Machines, University of Hannover, Hannover, Germany 3 Clinic for Small Domestic Animals, School of Vet...

background: human error is the most important cause of occupational and non-occupational accidents. because, it seems necessary to identify, predict and analyze human errors, and also offer appropriate control strategies to reduce errors which cause adverse consequences, the present study was carried out with the aim of identifying human errors while operating meat grinder and offer suggestions...

Deformation of the material during cyclic expansion extrusion (CEE) is investigated using upper-bound theorem. The analytical approximation of forming loads agrees very well with the FEM results for different amounts of chamber diameter, friction factor and also for lower die angles. However, the difference between analytical and numerical solution increases at higher die angles which are expla...

In this article, the effect of different yield functions on prediction of forming limit curve (FLC) for aluminum sheet is studied. Due to importance of FLC in sheet metal forming, concentration on effective parameters must be considered exactly in order to have better theoretical prediction comparing experimental results. Yield function is one of the factors which are improved by adding new coe...