Substructural phase transitions during intense plastic deformation of low-carbon ferrite-perlite steel

We have studied the evolution of the defect structure and phase composition of low-carbon ferrite-perlite steel subjected to intense plastic deformation using diffraction electron microscopy. It has been shown that a high degree of deformation is accompanied by disruption of the perlite columns. We have found and described two perlite decay mechanisms: decay of the carbide plates by a path of their granulation due to dislocation slip and dissolution of cementite arising from the outflow of carbon atoms from the carbide phase into ferrite crystal lattice defects. We have described the phenomenon of morphological reconstruction of the cementite-phase particles (a transition from layers to spheres) under plastic deformation conditions. Tomsk State Architectural and Construction University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 63–71, March, 1998.     

Behavior of the glass transition and crystallization temperatures of the oxide glass MgO-Al2O3-SiO2 under external influences

The kinetics of the glass transition Tg and crystallization Tcr temperatures of the glass MgO-Al₂O₃-SiO₂ is studied under conditions of annealing in the glass transition interval and after treatment with a pulsed magnetic field (PMF). It is found that all the parameters studied exhibit nonmonotonic and intercorrelated variations in time. These temporal variations are due to structural relaxation (SR) in the glass. It is observed that a relative decrease of T _g and T _cr occurs in the annealed or PMF-treated glass. This effect is important from the standpoint of modern ideas about the mechanisms of structural relaxation and is due to the concentrational redistribution of chemical bonds. The condition for externally induced anomalous behavior of the temperatures investigated is determined. Zh. Tekh. Fiz. 67, 30–34 (October 1997)     

Äquidensitometrie-eine Methode zur Beurteilung von Plasmen—XI: Untersuchung des Einflusses von NaCl und Ba(NO3)2 auf die Intensität von Linien und die Verteilung von Teilchen im Gleichstrombogenplasma der Silberstein-Methode

The influence of NaCl and Ba(NO₃)₂ on the intensities of atomic lines of Al, Sn and Be and on the axial particle distribution of these elements in the d.c. arc plasma was investigated. As the analytical method we used the procedure of Silberstein in which micro-amounts of solutions were added to the cathode and also to the anode. The time of evaporation, the temperature, the electron pressure, and the intensities of lines were investigated. We used the combination of spectral photography and photographic equidensitometry to derive particle distribution. The results of these investigations were: (1) NaCl and Ba(NO₃)₂ reduced the temperature of the plasma. The electron pressure was constant both in the presence of fairly large amounts of NaCl or Ba(NO₃)₂ and in the hotter arc without additive. (2) The enhancement of the intensities was best in presence of rather large amounts of Ba(NO₃)₂. (3) The maximum of the particle concentration was shifted, by additives from the cathode, towards the middle of the arc. We found a correlation between intensity and this shifting. In the arc with Ba(NO₃)₂ the most homogeneous plasma was obtained.     

Investigation of gallium arsenide containing coppee as a material for photoresistor receivers

The properties of gallium arsenide doped with copper are investigated for different modes of diffusion, as a material for the sensitive elements of a photoresistor IR receiver. The procedure for obtaining specimens with the required parameters is established, and the material obtained is used to manufacture photoresistors. The threshold sensitivity P_t of a photoresistor receiver with microwave bias based on gallium arsenide doped with copper reaches the values obtained in photoreceivers based on germanium doped with gold, but the GaAs:Cu photoreceiver has a more rapid response. The detection capability D^*of a GaAs:Cu photoresistor receiver with microwave bias considerably exceeds the values of D^* of a photoreceiver with a constant bias using the same material.