Free Energy Calculation of Al-Li-Mg Alloy from Electron Level
Based on Thomas-Fermi model£¬the calculation method of free energy for atom cluster with electric field had been found. The change trend of free energy of Al-Li-Mg alloy under the effect of electric field had been calculated systemically and quantitatively. And following results had been given: mostly the free energy of Al3Li andMg5Al8 at aging temperature is lower than that of free energy at solid solution temperature, but once the negative electric field increased to certain degree there will be opposite result. At aging temperature, the free energy ofAl3Li and Mg5Al8 are lower than that of Al-2.14wt.%Li andAl-2.6wt.%Mg. And comparing with 1420 alloy, the electric field promotes the precipitation of Al3Li and restrains the precipitation of Mg5Al8.
Influence of an electric field on the plastic deformation of polycrystalline NaCl at elevated temperatures
Abstract The effect of a d.c. electric field of 1 kV/cm on the plastic deformation of polycrystalline 99.9% NaCl was determined in compression at 23–532°C (0.28–0.75  T M ) and strain rate e =8.3×10 −4  s −1 . Upon removing the effect of Joule heating it was found that the reduction in the flow stress produced by the field increased with temperature from 0.28 to 0.4  T M , reached a maximum at 0.4  T M and then decreased, becoming nil at 0.75  T M . It is proposed that the reduction in flow stress resulted from an enhancement of cross-slip due to an increase in stacking fault energy. The field had no detectable effect on the plastic deformation kinetics at constant structure in the temperature range 0.28–0.6  T M (cutting of forest dislocations), nor did it appear to have a significant influence on dislocation glide and climb at 0.75  T M .
Plasticity of polycrystalline ionic solids
Alkali and silver halide polycrystals prepared by extrusion are deformed in compression and in tension at different temperatures. The results show that the critical flow stress of these materials is determined by the activation of secondary {100} 〈110〉slip as long as there is no strong [100] fibre texture. This is necessary to fullfill the von Mises criterion. On the other hand, the ductility is correlated with the change of the slip mode on {110} planes from planar to wavy. Waviness is generated by the cross slip of dissociated screw dislocations and the motion of edge dislocation jogs produced on the cross slip plane. Of these processes the one dominates which requires the strongest activation. The experimental results show contrary to previous statements that the change in slip mode does not necessarily occur at the temperature at which secondary slip becomes easy. 
 
 
 
Durch Extrusion hergestellte Alkali- und Silberhalogenidpolykristalle werden durch Druck-und Zugbeanspruchung bei verschiedenen Temperaturen deformiert. Die Ergebnisse zeigen, das die kritische Fiesspannung dieser Materialien solange durch die Aktivierung sekundarer {110} 〈110〉-Gleitung bestimmt wird, wie keine starke [100]-Fasertextur vorhanden ist. Dies ist fur die Erfullung des von Mises-Kriterium notwendig. Andererseits ist die Duktilitat mit der Anderung der Gleitmode auf {110}-Ebenen von planar zu wellig verknuipft. Wellig-keit wird durch Quergleitung aufgespaltetener Schraubenversetzungen und der Bewegung von Sprungen von Stufenversetzungen auf der Quergleitebene erzeugt. Von diesen Prozessen dominiert derjenige, der die starkste Aktivierung erfordert. Die experimentellen Ergebnisse zeigen im Gegensatz zu fruheren Feststellungen, das die Anderung der Gleitmode nicht notwendigerweise bei Temperaturen auftritt, bei denen sekundare Gleitung einfach wird.