Multiphase microstructure in steel bars produced by dieless drawing

In the dieless drawing technology the drawing dies are replaced by a heating device, generally by an induction coil. Bars of different cross-sections, round or even rectangular, with varying dimensions along the length can be produced. By using a cooling box in connection with the heating device this deformation process may also be employed for a thermomechanical treatment of steels. The special cooling strategy with low cooling rates at high temperatures (during ferrite formation) and higher cooling rates at lower temperatures favours the formation of multiphase microstructures (ferrite - bainite/martensite) with a low yield strength but a strong work hardening effect. The experiments were carried out on rods with a diameter of 16 mm of a plain low carbon steel (0.1%C, 0.7%Mn). The specimens were locally heated up to the maximum temperature ?_max that initiates the dieless drawing process, and subsequently cooled with different coolants. The change in yield strength and tensile strength and the corresponding change in the ratio of both could be achieved by variation of ?_max and the cooling conditions. The multiphase microstructure with desired mechanical properties was produced at a strain of about more than 0.45 within the region of ?_max ≈ 900–1000°C and a finale cooling rate of about 20 K/s.     

Theoretical and experimental investigations into dieless drawing

Some experimental and theoretical results are presented for the dieless drawing method. Because of the absence of a rigid die considerable flexibility is reached by this method. For example it is possible to achieve very high strains in one pass. Unlike in conventional drawing it is possible to produce parts with variable cross‐sections along the length by varying the drawing velocity appropriately. This is demonstrated theoretically and experimentally. To model this process a simple one‐dimensional disk model is suggested. The resultant temperature distribution is compared with previous calculations.     

Beckmann's Studio Computers Specified for Early Computer Art

When the pioneers of computer art started to produce their works by programming mainframes, using plotters for output, the Austrian sculptor Otto Beckmann took a different path. He used a special computer constructed by his son Oskar Beckmann. This article describes the technical context of early computer art, Beckmann's interdisciplinary team ars intermedia, and the development of nonconventional studio computers.     

Versuchsmethodik für Laboruntersuchungen zum Zusammenhang zwischen Herstellungsbedingungen,Gefüge und Werkstoffeigenschaften

Wegen ihrer großen Bedeutung unter den heutigen Herstellungsverfahren wurden thermomechanische Behandlungen durch Warmflachstauchversuche mit dem Warmumformsimulator (Wumsi) des Max-Planck-Instituts für Eisenforschung durchgeführt. Die gegenüber anderen Simulationsverfahren vergleichsweise großen Wumsi-Proben erlaubten erstmalig mit aus ihnen entnommenen 1/2 CT-Proben auch die Durchführung von Bruchmechanikversuchen an im Labor thermomechanisch behandeltem Stahl. Hierbei wurden die Meßwerte mit einem Laborrechnersystem für die spätere Auswertung gespeichert. Die beschriebene Versuchsmethodik wird exemplarisch mit Versuchsergebnissen an dem Vergütungsstahl 50 CrMo 4 illustriert. Neben einer thermomechanischen Behandlung mit vier simulierten Walzstichen wurde eine konventionelle Vergleichsvariante erzeugt; die Proben wurden bei verschiedenen Temperaturen angelassen. Sowohl bei den Ergebnissen der Zug- und Kerbschlagbiegeversuche, als auch bei den bruchmechanischen Kennwerten Rißzähigkeit K_Ic und J_R-Rißwiderstandskurven zeigte sich die Verbesserung der Werkstoffeigenschaften durch die thermomechanische Behandlung gegenüber denen nach der konventionellen Behandlung.     

Farbmessungen auf dem Gebiete der Lebensmitteluntersuchung

Ohne Zusammenfassungbedeutet mit Abbildungen.     

Ein Beitrag zum Förderprinzip periodisch arbeitender,ventilloser Pumpen

Ohne Zusammenfassung Schlu? des Aufsatzes in Forsch. Ing.-Wes.29 (1963) Nr. 2 S. 47/56.     

Contrasting the use of tools for presentation and critique: Some cases from architectural education

This study investigates video recordings of design reviews in architectural education, focusing on how presentations and discussions of designs are contingent on the specific tools employed. In the analyzed recordings, three different setups are utilized: traditional posters, digital slide-show technologies, and combinations of the two. This range of different setups provides a set of contrasts that make visible the role of technologies in shaping the ways in which the reviews are conducted. The analysis is structured in three themes. First, we examine the sequential organization of digital presentations in relation to the spatial structure of poster-based presentations. Second, the different ways in which shared attention is established in digital, paper-based, and hybrid presentation practices are analyzed. Third, we address part-whole relations—how details in presented materials are put in relation to the overarching project or the presentation as a whole. Taken together, the analyses suggest that the detailed organization of the design review is transformed in subtle yet consequential ways through the introduction of digital slide-show technologies. These transformations are consequential not only locally, for the design review itself, but also for the instructive work that is accomplished through this practice. We conclude by discussing some implications for design, arguing that an increased awareness of how the practice is influenced by the different setups might be key for the proper adaptation of presentation technologies to particular purposes.