372595873

ANALYSIS, TESTING

JPRS-UMS-92-003 16 March 1992

UDC (548.5+537.311 ):621.315.5

[Abstract] InSb foils and InSb-InBi systems containing up to 4% InBi are produced by crystallizing a 0.3 g alloy drop splashed onto a polished inner surface of a rapidly spinning copper cylinder, resulting in 20 to 60 pm foils. Under such crystallization conditions, the cooling ratę reaches 10⁶K/s. The foils are investigated metallograph-ically under an MMU-3 microscope and by an X-ray phase analysis in a DRON-3 diffractometer. The foil texture is examined by the inverse pole figures method. The pole density distribution of diffraction lines in rapidly ąuenched InSb foils and InSb-InBi systems is examined and summarized and the temperaturę depcn-dence of their resistivity, Halfs coefficient, differential thermoelectromotive force, and Hall electron mobility is plotted. An analysis demonstrates that rapidly quenched InSb foils and InSb-InBi systems have a polycrystalline structure and are characterized by a crystallographic plane-111 + crystallographic plane-110 texture. A decrease in the electron mobility with an increase in the bismuth concentration in indium antimonide is attrib-uted to the refining of the granular structure and, as a conseąuence, an enhancement of electron scattering on the grain boundaries and scattering on ionized bismuth atoms. Figures 1; tables 2; references 7: 6 Russian; 1 Western.

The Physicochemical Properties of a Cdj__xMn_xTe Surface With Varying Mn Contents

927D0067B Moscow POYERKHNOST: FIZIKA, KHIMIYA, MEKHAN1KA in Russian No 12, Dec 91 (manuscript received 22 Feb 90; after revision 19 Dec 90) pp 18-23

[Article by Ye.V. Buzaneva T.A. Vdovenkova, G.D. Popova, V.I. Strikha, A.I. Tsyganova, A. Rodzik, and E. Chametska-Sukh, Kiev State University]

UDC 537.311.33

[Abstract] The authors of the study examincd the physicochemical properties of Cd,__xMn_xTe (x = 0, 0.34, and 0.7) after spalling in air and after mechanical polishing, etching in a 12-15% or 3-5% solution of Br₂ in methanol, rinsing in methanol, and drying. The specimens’ surface composition was studied by scanning Auger electron spectroscopy as described elsewhere. Etching the test specimens in a 12-15% solution of Br₂ in methanol was found to cause the specimen surfaces to become highly enriched in tellurium and to result in lower oxygen and tellurium oxidc contents on the specimen surface than when a 3-5% Br₂-in-methanol solution was used. The experiment results were found to be in good agreement with those predicted by a thermodynamic analysis of the possible reactions between Cd, Mn, Te, etching agent, oxygen, and water that the authors performed before conducting the actual experiments. Specifically, Cd, Te, and C were found to be morę uniformly distributed in the specimen surfaces than Mn and O were. The sections with the highest manganese content also contained the highest amount of oxygen. In a near-surface layer about 10 angstroms thick, the etched specimens of Cd,._xMn_xTe studied were found to contain Te, Te0₂, and Mn0₂ with forbidden band widths that differed from those of the starting Cd,._xMn_xTe (x - 0, 0.34, 0.7). The two deep-level bands discovered in specimens of Cdo ₆₆Mn₀ 34Te were hypothesized to be linked not only to structural defects but also to the electron States in the conduction bands of Tc, Te0₂, and Mn0₂. Figurę 1; references 8: 5 Russian, 3 Western.

Determination of the Dependence of Acoustic Emission Parameters on Deformation During the Simple Bending of Composites Consisting of Materials With DifTerent Strengths

927D0066 Kiev PROBLEMY PROCHNOSTI in Russian No 12, Dec 91 (manuscript received 25 Jun 90) pp 51-56

[Article by Ye.Z. Korol, Mechanics Institute, Moscow State University, Moscow]

UDC 620.179

[Abstract] The author of the study worked to develop a series of formulas for use in determining the dependence of acoustic emission parameters on deformation during the simple bending of composites consisting of materials having difTerent strengths. He develops a series of formulas that enable him to give consideration to the fact that the deformation properties of such materials depend on the type of stress-strained State (e.g., compression, tensile) in which the composite happens to be and that, under conditions of simple bending, such materials will have a nonuniform stress-strained State consisting of a tensile stress zonę and a compression strength zonę. The author derives a set of finite formulas for the case of degenerated nuclei. Formulas are presented for use in calculating the stresses that develop in composites consisting of materials having difTerent strengths when the said composites are subjected to a specified bending moment and lengthwise force. Formulas are also presented for use in calculating the deformations developing in the outer fibers of any section. The author selects a laminar composite to study the particular cases of one acoustic emission source, two simultaneously acting acoustic emission sources, and two acoustic emission sources where the second follows the other after some specified delay. The author recommends that his new method and the diagrams resulting from its use be used in the nondestructive diagnosis and forecasting of the mechanical States of composite materials and structures such as those studied when they are in both uniform and nonuniform stress-strained States. Figures 3; references 2 (Russian).