| Abstract: | Plastification was in focus of research on metals and alloys in the first third of the 20th century. Wichard von Moellendorff built up a research laboratory at the “Allgemeine Elektricitätsgesellschaft” (AEG) in Berlin‐Oberschöneweide in the “Kabelwerk Oberspree” (KWO). With systematic investigations on the metallographic and mechanic properties of metals and alloys he made substantial contributions to the scientific discussion of plastification. His results were partially contrary to the current opinion in metal science, but nevertheless true. Together with Czochralski he derived first conceptions on the mechanism for such deformations considering the crystalinity of the metals. After an interruption due to the first world war, Moellendorff started investigations as director of the “Staatliches Materialprüfungsamt” and the “Kaiser‐Wilhelm‐Institut für Metallforschung” on the plastic flow conus of metallic rods during rupture. This process was explained in 1929 by “turning, distortion and shearing of crystallographic planes”. Polanyi at the Kaiser‐Wilhem‐Institut für Faserforschung, was able to explain the mechanism in 1932. Single atoms move step by step through the lattice on inclined positions and form dislocations. Together with neighbored atoms whole plains can be moved with a minimal energy through the crystal. With the dislocation mechanism, hammering, rolling and bending of metals and alloys can be explained. 1933 Polanyi left Nazi‐Germany and became Professor in Manchester, Moellendorff was brave enough to make an affront against the Nazi regime in giving up the membership of the Kaiser‐Wilhelm‐Gesellschaft stating his personal opposition in an official letter which was not widespread behaviour of the German scientific and technical elite. |
