Effect of Nd, Pr substitutional atoms on the magnetic and magnetostrictive properties in (Tb-Dy)(Fe-Co)2 Laves phases

Polycrystalline TbxDy1-xR0.1Fe2-zCoz (R = Nd, Pr, x = 0.2, 0.3; z = 0, 1.3) cubic Laves phase alloys with MgCu2-type structure were prepared by arc melting followed by homogenizing annealing. The crystal structure, magnetic properties, and magnetostriction have been investigated. Compounds with high values of magnetostrictive susceptibility were found in the temperature range 150-300 K. Compounds with partial substitution of cobalt for iron demonstrate a change in the sign of anisotropic magnetostriction. This work continues the search for magnetostrictive materials with inexpensive neodymium and praseodymium.

Influence of homogenizing annealing on reducing the content of δ-ferrite in high-strength high-chromium martensitic steel grade 07Kh15N5D4B obtained by selective laser alloying

The work studies effects of temperature – time parameters of homogenizing annealing and related structural changes on the content of δ-ferrite in high-chromium martensitic steel grade 07Kh15N5D4B, obtained by selective laser alloying. It is shown that homogenizing annealing at a temperature of 1150°C with a holding time for 8 hours reduces the content of δ-ferrite, eliminates the cellular structure, and also increases the strength properties of the above-mentioned steel.

Membrane Surface Morphology before and after the Reversible Hydrogen Doping of Diffusion Filters

Atomic force microscopy (АFМ) and high-precision scanning electron microscopy methods were used to study the surface of diffusion filter-membranes of alloy Pd93Y7. The formation of alterations in structure in one of membranes was established as a result from the homogenizing annealing at 900°C for 1 hours. It was found that the reversible doping of the membrane alloy with hydrogen caused the dispersion of the diffusion filter-membranes’ surface structure. Differences in changes by the surface structure are determined during the hydrogenation in directional and non-directional flow of hydrogen.

Production of pure nickel alloys doped with sulfur and phosphorus

A procedure for alloying nickel with sulfur and phosphorus by diffusion and homogenizing annealing is described using the example of pure nickel (RRR at 600). A scheme of the installation for alloying from the gas phase is described. The possibility of uniform alloying with sulfur and phosphorus of samples and material in the form of plates or foils with a thickness of 0.2 mm or thinner at a concentration ranging between 0.001 and 0.08) at. % is shown. Diffusion annealing is carried out after heating and pumping out in a high vacuum and without contamination, in a quartz volume containing sulfur or phosphorus vapors at a temperature of 1100 to 1200 °C. By choosing the ratio of the masses of the alloyed material and the corresponding filling of sulfur or phosphorus, it is possible to predict in advance the resulting concentration of impurities with a sufficient time of annealing. The impurity concentration is uniform in volume within ten percent. Modeling and control annealings with the measurement of the residual resistivity of the control samples allows you to evaluate the results obtained.

Structure-Properties Correlation of Lead Selenide-Lead Selenite Composite

The main areas of work are related to the synthesis of a two-phase composite (1-x)PbSe·xPbSeO3 in the form of a powder, faceted single crystal, film and compacted material with the possibility of changing the fraction (x) of the PbSeO3 phase from 0 to 1 by oxidation of PbSe in a dry atmosphere in the temperature range 20-550 °С and the study of its physicochemical properties. All initial samples are obtained by the original method from Pb1-ySey powder, in which the composition corresponds to the maximum melting temperature of the compound and is defined as ysmax=0.500025±0.000025 at. Se. The powder is crushed, after which homogenizing annealing is performed at a constant temperature (~750 °C) in a dynamic vacuum in order to achieve the minimum general pressure condition. The noted precursor-related technological procedures are necessary to achieve congruent evaporation conditions in all types of samples and help minimize the concentration of inherent defects and inclusions in phase two. Depending on application, it is possible to form crystalline powders with a given ratio of volumetric phases PbSe and PbSeO3 in a separate grain. For all cases, the "shell" for semiconductor particles PbSe is the dielectric phase PbSeO3. The principal possibility of forming the smallest (up to nanometer) grains of lead selenide in the dielectric matrix of lead selenite is shown. According to the proposed method, the synthesis of lead selenite by oxidation of lead selenide is possible.

Use of Homogenizing Annealing for Formation of the Structure and Properties of Cast Blanks Produced from the Alloys Obtained by Aluminothermy

This paperwork presents the results of a series of experiments on the use of homogenizing annealing, aimed at the possibility to control the structure and properties of steel samples obtained by aluminothermy. This method of processing, in some cases, allows to eliminate the need to use subsequent heat treatment operations due to the achievement of the required properties by the cast blank material. Refractory materials and thermite mixtures used, conditions for the production of castings and their total chemical composition are given. The tensile diagram analysis of the samples before and after heat treatment is presented; the structures and diffraction patterns of the samples’ destruction spots are considered. The material obtained by aluminothermy corresponds in its chemical composition to A1, A2, A3, A4 grade of steels for the rail transport according to GOST 31334-2007 which are used in the manufacture of locomotive axes and other rolling stock.