Some features of the chemical transformation of a highly exothermic ore concentrate-based mixture in a combustion wave

Use of inexpensive ore concentrates as initial components in SHS metallurgy [1–3] brings about some specific features in the process and the properties of the materials obtained. Ore reagents contain a considerable amount of impurities (Al₂O₃, SiO₂, Fe₂O₃) that decrease the energetics of SHS systems and the temperature and the rate of combustion and create the limits of combustion and phase separation. In addition, the impurities participate in chemical reactions and enter the desired product. In many cases the presence of silicon, iron, and aluminum in a cast product does not prevent use of this product for practical purposes.Institute of Metallurgy, Academy of Sciences of the Republic of Georgia, Tbilisi. Institute of Structural Macrokinetics, Russian Academy of Sciences, Chernogolovka. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 65, No. 5, pp. 613–616, November, 1993.     

Synthesis and analysis of transformer-isolated converters

A systematic and straightforward procedure is developed for the synthesis and analysis of transformer-isolated power converters. The procedure can be used to determine the ranges of duty-ratio over which the transformer-isolated power converters of a given class can be operated without transformer saturation. The procedure can also be used to study the dependence of the power converter switch stresses on duty-ratios. This information is useful in the selection of the transformer-isolated power converter most suitable for a given application and in the design of this power converter with minimum switch stresses, high power density, and low cost     

Variation of the creep limit and structure of a welded joint in PT-3V titanium alloy under the effect of cyclic loading. Report 2

Comparative analysis of the characteristics of amplitude-dependent internal friction (IF) was carried out to explain reasons leading to an increase of the creep limit of the butt welded joint in PT-3V titanium alloy (PT-2V filler material) after cyclic loading. IF was measured by the method of the direct torsional pendulum on cylindrical specimens representing the gage part of the specimens subjected to preliminary cyclic loading. The data were processed using the Granato-Lucke theory. The results show that the reduction of IF after cyclic loading took place as a result of an increase of the number and redistribution of pinning points of the dislocations. Consequently, the density of mobile dislocations decreases by 8% and the length of dislocation segments by 18%. These processes of stabilization of the structure were completed within 5·10 ⁴ cycles of preliminary loading. Stabilization of the dislocation structure of the material of the welded joint increases its creep limit.Translated from Problemy Prochnosti, No. 4, pp. 35–40, April, 1996.     

Experience in High-Temperature Thermomechanical Treatment with Helical Reduction in the Production of Axisymmetric Parts

Metal Science and Heat Treatment -     

Quality of the surface of strip annealed in bell-type furnaces

Institute of Ferrous Metallurgy. Novolipetsk Metallurgical Combine. Translated from Metallurg, No. 11, pp. 32–33, November, 1989.