Papers by Keyword: Structural Transformation

Abstract: The article contains the results of experiments carried out on laser irradiation of steels in a constant magnetic field. The experiment shows it possible to increase the cooling speed while heat transfer decreases from the surface into lower metal layers, which slightly reduces laser-hardened layer depth, increases convective mixing of the fusion area, which have a positive impact on the surface layers quality of steel and alloys. This has a positive effect on strength product properties. Magnetic field processing of metal reduces the degree of local plastic deformation of irradiated layer due to magnetostriction phenomenon. Magnetic field superimposition contributes to two-phase decay of the martensite, and reduces residual stresses and crack risk.

Abstract: A unidireon heating, followed with a ferromagnetic- paramagnetic transition in austenite for the produced unidirectional crystal. Under a magnetic field change of 3 T, the total effective refrigeration capacity was strikingly enhanced up to 125 J/kg, nearly 64% higher than that of polycrystalline master alloy ctional crystal of Heusler Ni₅₀Mn₃₇Sn₁₃ material was produced using a modified high-pressure optical zone-melting furnace. A structural transformation between weak-magnetization martensite and ferromagnetic austenite occurred first up(76 J/kg). The modified high-pressure optical zone-melting technique demonstrated high potentials for the fabrication of super-performance Heusler Ni-Mn-based magnetocaloric materials.

Abstract: The results of the study of structures forming in magnetic colloids with magnetized aggregates under the action of an elliptically polarized rotating magnetic field are discussed. When a magnetic colloid layer with magnetized aggregates is affected by an elliptically polarized rotating magnetic field, some ordering of the structural lattice is observed, which is determined by the frequency and orientation of the rotating magnetic field polarization ellipse as well as by the value of an additionally imposed steady magnetic field.

Abstract: The approach to studying the structure of economy is determined by the nature of the national economy as a system. Identification of the economic system development mechanism will help identify the opportunities to influence its structure. It was found out that on the basis of the study of the mechanism of maintaining the integrity of the system in its development it becomes possible to achieve the most effective application of the systematic approach using conceptual studies of functioning of economic systems in the basic areas of economic theoretical studies. Based on the dynamic aspects of systems concept, it is proposed to focus the study of the problems of the economic structure development on the mechanism of structural shifts.

Abstract: In bimetallic cluster, research on the frozen structure with the changing concentration plays an important role in exploring new structural materials. This paper studies the freezing processes of (AgCu)₃₀₉ clusters with different Ag concentrations. The results indicated that the structural transformation was strongly related to concentration. It was found that the frozen structures were changed form icosahedron, hcp and fcc-hcp with the change of Ag concentration. The frozen structures were formed icosahedral for the clusters with Ag concentration at 10%, 20%, 30%, and the pure Ag₃₀₉. For the clusters with Ag content at 40%, 50%, 60%, 70%, and 80%, the frozen structures were formed defect icosahedral. It was also found that the frozen structure have hcp character for the pure Cu₃₀₉ cluster. Meanwhile, the frozen structure of (AgCu)₃₀₉ with 90% Ag concentration was formed fcc-hcp structure. The segregation effects of the Ag-Cu are the key reason for the structural transformation.

Abstract: In bimetallic clusters, the component and position of doping atoms can influence on structures and properties. It may induce irregular physical and chemical properties by tuning the doping atoms. In this study, (PdAg)₃₀₉ clusters with different contents and positions of doping Ag atoms have been investigated by molecular dynamics simulation based on the embedded atom method. It is found that the structure of (PdAg)₃₀₉ clusters transformed from truncated octahedron to icosahedron, and melting in heating processes from 200 K to 1500 K. Results indicated that the temperature of structural transformation and melting are strongly related to the number and position of doping Ag atoms. The melting point decreased with the increased Ag atoms, but there is irregular by doping Ag atoms at different position. The structural transformed temperature from truncated octahedron to icosahedron decreased with the increasing Ag atoms and the outer doping position. This means that the effect of doping Ag atoms can be used to tune the special structures of bimetallic clusters.

Abstract: The irregular physical and chemical properties can induce by the synergy effects of alloy elements in bimetallic clusters. Research on the influence of alloys concentration on the frozen structure of bimetallic cluster plays a key role in exploring new structural materials. In this paper, the influence of the Cu concentration on the frozen structures of the (CoCu)₃₀₉ clusters was investigated by using molecular dynamics simulation based on an embedded atom method. The (CoCu)₃₀₉ clusters with different Cu concentration were frozen from 2000 K to 200 K. It was found that the Co₃₀₉ cluster was formed by the Co bulk-like hcp structures and the Cu₃₀₉ cluster was constructed by the form with a 5-fold symmetry axe. The icosahedron structural transformation is strongly related to doping Cu atoms. Furthermore, two methods of icosahedrons structural transformation were found during the freezing processes of the Co-Cu clusters with different Cu concentration. The irregular phenomenon of the structure transformation induced with the 30% and 40% Cu concentration. The synergy effects of the Co-Cu on the surface are the key reason for the irregular icosahedrons.

Abstract: In view of high energy consumption situation in the apparel industry in the background of green economy, the author explores the multi-functional structural design method for single garment and the diversified wearing forms of single product according to the study on clothing style change, so as to satisfy the individualized and special needs of consumers. This not only improves the energy efficiency of clothing materials, but also optimizes life cycle of products, and accordingly promotes the environment-friendly clothing philosophy and provides new solution to the contradiction between mass production and individualized consumption of garments.

Abstract: In this paper, wool yarns and the slenderized wool yarns were used as raw materials, and knitted under the same process parameter, many methods of testing were applied to analysis the wearing characteristics, An series of experiments show that there was a significantly improvement in the anti-pilling performance and air permeability, and the stiffness of the sample became smaller, increasing soft and comfort, but it had little effect on crease- resistance. The slenderizing not only improved the spinning count, but also enhanced the knitted properties by the structural transformation, was a good choice to develop the high-grade wool knitwear.

Abstract: The X-ray diffraction and specific heat measurements have been performed for the ferromagnetic compounds (MnCo)_1-xGe within the concentration range 0.02 x 0.035. The compounds possess the hexagonal Ni₂In-type structure at elevated temperatures, while for the composition with x = 0.02 and 0.03 a spontaneous martensitic-type transition to the orthorhombic TiNiSi-type phase occurs at 283 and 221 K, respectively. We studied the entropy changes associated with the first-order structural transition and estimated the changes in magnetic, lattice, electronic entropies.