Forging of Mg‐Alloys AZ31 and AZ80

Mg‐wrought alloys recently became an engineer material of constantly increasing interest. The mechanical properties of extruded Mg‐feedstock of the alloys AZ80 and AZ31 indicate their suitability for automotive applications in form of high‐quality forgings. Therefore a detailed knowledge about the forming behaviour is of particular importance. In order to compare mechanical properties of available Mg‐feedstock qualities compression tests at room temperature have been carried out by applying batches of AZ31‐ and AZ80‐feedstock. Cylindrical specimens were made out of received continuously casted as well as extruded AZ31‐ and AZ80 ‐ rods. A quantitative analysis of Mg‐feedstock’s microstructure has been carried out. The characterization of the deformability of applied Mg‐feedstock under hot working conditions could be performed by means of uniaxial plain strain upsetting tests at temperatures between 300 and 450 °C as well as logarithmic strain rates of 10^‐1, 1 and 10s^‐1. It is shown that the chosen parameter range ensures an enhanced deformability of continuously as well as extruded Mg‐feedstock. The subsequently carried out determination of microstructural evolution could be related to obtained flow stress curves of applied batches of Mg‐feedstock. Furthermore, FVM/FEM‐systems have been employed in order to design a simplified geometry of heated forging dies suitable for forging tests. The tests have been carried out by means of a hydraulic press. During the tests their punch velocity has been varied between 1 and 40 mm/s. Hence numerically simulated results could be confirmed by practical tests. Exemplary forgings of a simplified shape were made out of all applied batches of Mg‐feedstock. No remarkable failures have been detected.     

Understanding the Radiobiological Mechanisms Induced by 177Lu-DOTATATE in Comparison to External Beam Radiation Therapy

Radionuclide Therapy (RNT) with ¹⁷⁷Lu-DOTATATE targeting somatostatin receptors (SSTRs) in neuroendocrine tumours (NET) has been successfully used in routine clinical practice, mainly leading to stable disease. Radiobiology holds promise for RNT improvement but is often extrapolated from external beam radiation therapy (EBRT) studies despite differences in these two radiation-based treatment modalities. In a panel of six human cancer cell lines expressing SSTRs, common radiobiological endpoints (i.e., cell survival, cell cycle, cell death, oxidative stress and DNA damage) were evaluated over time in ¹⁷⁷Lu-DOTATATE- and EBRT-treated cells, as well as the radiosensitizing potential of poly (ADP-ribose) polymerase inhibition (PARPi). Our study showed that common radiobiological mechanisms were induced by both ¹⁷⁷Lu-DOTATATE and EBRT, but to a different extent and/or with variable kinetics, including in the DNA damage response. A higher radiosensitizing potential of PARPi was observed for EBRT compared to ¹⁷⁷Lu-DOTATATE. Our data reinforce the need for dedicated RNT radiobiology studies, in order to derive its maximum therapeutic benefit.     

The effect of increasing soaking time on the properties of premixing starch–glycerol–water suspension before melt-blending process: comparative study on the behavior of wheat and corn starches

Polymer Bulletin - The reduction in the torque consumed during the preparation of thermoplastic starch to the minimum value was achieved by reaching equilibrium state of the premixing suspension of...     

Hydromechanisches Tiefziehen und Hochdruckblechumformung als Verfahren zur Herstellung komplexer Bauteile aus Magnesiumfeinblechen des Typs AZ31B‐0

Hydro Mechanical Deep‐Drawing and High Pressure Sheet Metal Forming as Forming Technologies for the Production of Complex Parts Made of Magnesium Sheet Metal AZ31B‐0 Semi ‐ finished sheet ‐ metal products made of magnesium alloys such as AZ31B are known as better deformable at temperatures in the range of 175 °C ‐ 240 °C. By means of hydroforming technologies, as there are hydro mechanical deep‐drawing and high pressure sheet metal forming, the influence of different forming parameters on the forming results has been investigated. A more complex experimental geometry was deformed applying forming temperatures of 175 °C, 200 °C, 225 °C and 240 °C and accordingly adjusted forces of the blank holder. Concerning the applied forming ‐ methods and experimental parameters the forming results have been evaluated and compared regarding the decrease of sheet thickness and the development of small radii. For some experimental parts, which have been deformed by means of high pressure sheet metal forming at temperatures of 175 °C and 225 °C, supplementary investigations have been carried out in order to determine the evolution of characteristic surface values in dependence on the forming operation. On the basis of these results practical recommendations for the limits of application of aforementioned forming technologies for AZ31B‐0 magnesium sheet metal are given.