The performance of hot-forging dies, in which the die cavity is weld-deposited with a layer of modified H12 hot-work tool steel, has been studied, using a continuous monitoring of the die condition as well as macroscopic and microscopic examination. It was observed that the thickness of the hard upper ‘capping layer’ and that of an intermediate ‘buffer layer’ have a pronounced effect on the lif...

Although deep drawing process in the macro scale are well developed, the known concepts cannot be applied to micro deep drawing through directly scale down the specimen and tooling size due to the so-called size effects. Therefore, tensile test and micro deep drawing experiments were conducted to generate the knowledge for the micro deep drawing process. Stainless steel 304 foils with 4 differe...

Improvement of die life in the hot forging of brass alloys is considered vital from both technical and economical points of view. In this research, pin-ondisc tests were carried out at a range of temperatures to evaluate the influence of plasma nitriding and duplex nitriding-physical vapour deposition (PVD), including TiN-TiAlN and TiN-TiAlN-CrAlN coatings, on the tribological properties of AIS...

background and aims. one of the major problems of all-ceramic restorations is their probable fracture under occlusal force. the aim of the present in vitro study was to compare the effect of two marginal designs (chamfer and deep chamfer) on the fracture resistance of all-ceramic restorations, cercon. materials and methods. this in vitro study was carried out with single-blind experimental tech...

Effektive Visualisierungen sorgen dafür, dass sich massenhaft vorrätige Zeitreihendaten, wie sie oftmals in Umweltprojekten generiert werden, dem Nutzer verständlich erschließen. Besonders dann, wenn solche Daten der Öffentlichkeit zugänglich gemacht werden sollen, ist es unabdingbar, geeignete Präsentationsformen zu wählen. Zu diesem Zweck werden interaktive, webbasierte Visualisierungstechnik...

Hot–press forming steels are formed in a fully austenitic state followed by die– quenching in order to generate martensite and achieve a strong steel. The ductility however, tends to be limited. We explore in this work a novel steel design in which the forming operation is in the two–phase austenite and ferrite field, so that the quenching results in a dual–phase ferrite and martensite microstr...

Soft ferromagnetic Fe-based bulk metallic glass key-shaped specimens with a maximum and minimum width of 25.4 and 5 mm, respectively, were successfully produced using a high pressure die casting (HPDC) method, The influence of die material, alloy temperature and flow rate on the microstructure, thermal stability and soft ferromagnetic properties has been studied. The results suggest that a stee...

The design of multi stage deep drawing processes requires the evaluation of many process parameters such as the intermediate die geometry, the blank shape, the sheet thickness, the blank holder force, friction, lubrication etc..These process parameters have to be determined for the optimum forming conditions before the process design. In general sheet metal forming may involve stretching drawin...

Sapphire dies (of single-crystal aluminum oxide) are used to obtain interfacial conditions along the contact surface of the die in a strip-drawing operation. Several solutions based on slip-line field analysis and upper-bound techniques are available for metal-forming problems. However, these solutions generally neglect elasticity and work-hardening and assume that friction is constant along th...