Revisiting Some Prospects for the Further Development of Ideas by Academician V.N. Antsiferov in the Field of Structural Powder Materials

2019 ◽  
Vol 60 (6) ◽  
pp. 682-686
Author(s):  
V. Yu. Dorofeyev
Keyword(s):  
Powder Materials ◽  
Further Development ◽  
Structural Powder

scholarly journals On some prospects for further development of Academician V.N. Antsiferov ideas in the field of structural powder materials

2019 ◽  
pp. 8-13
Author(s):  
V. Yu. Dorofeyev
Keyword(s):  
Lower Bainite ◽  
Supercooled Austenite ◽  
Powder Materials ◽  
Inhomogeneous Materials ◽  
Trip Steels ◽  
Wear And Corrosion ◽  
Bainite Structure ◽  
Further Development ◽  
Structural Powder ◽  
Powder Steels

The paper discusses the further development of some ideas of V.N. Antsiferov and the scholar school created by him in obtaining structural powder materials and products. The prospects for obtaining concentration-inhomogeneous steels and trip-steels are noted. The great potential lies in the control of the thickness and volume of the zone of deformation martensitic transformation occurring during fracture. It is advisable to continue the preparation of fullerene- and nitrogen-containing powder compositions and to study the structural heredity of powder steels. The possibility of the synthesis of fullerene-containing phases during the liquidphase sintering of the iron–cast iron and iron–graphite compositions and their subsequent redistribution in the bulk of the material during dynamic hot pressing is worth noticing. Producing nitrogen-containing steels by mechanical activation of powders followed by sintering in dissociated ammonia is advisable to use for obtaining not only wear-and corrosion-resistant materials, but also heat-resistant ones. The studies on the decomposition of supercooled austenite in powder steels of various doping systems with different technological backgroung (sintered, hot-deformed, infiltrated, etc.) are promising. The potential for development is the research of hot-deformed concentration-inhomogeneous materials, obtained, in particular, on the basis of powders of the Distaloy type. The techniques developed by the Antsiferov’s school are significant. The most important one is the method for determining the concentration variation coefficient, as well as a magnetometric complex and a mathematical model, which makes it possible to predict the decomposition of supercooled austenite. Antsiferov’s works can be used for obtaining lean powder steels with the lower bainite structure, which provides the optimal combination of strength and toughness.

scholarly journals Methods for introducing carbon into the composition of structural powder materials

2021 ◽  
Vol 344 ◽  
pp. 01005
Author(s):  
Maxim Egorov ◽  
Rimma Egorova ◽  
Zanna Ereveeva
Keyword(s):  
Energy Consumption ◽  
Structural Strength ◽  
Structural Materials ◽  
Strength Characteristics ◽  
Powder Materials ◽  
Main Requirement ◽  
Sintered Powder ◽  
Structural Powder

Durability and reliability of machines and mechanisms depends on the structural strength of the products from which they are made. The main requirement for any product is trouble-free operation under the conditions of the established operational period. This determines the requirements for structural materials, the main of which are technological, operational and economic. The production of sintered powder products ensures the lowest energy consumption and the lowest waste. The introduction of carbon into powder materials significantly increases the strength characteristics of the product.

Application of TEM to Deformation, Wear, and Fracture of Ceramics

1974 ◽  
Vol 32 ◽  
pp. 472-473
Author(s):  
B. J. Hockey
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Mechanical Behavior ◽  
Brittle Materials ◽  
High Temperature Strength ◽  
Wide Range ◽  
Corrosive Environments ◽  
Further Development

Ceramics, such as Al2O3 and SiC have numerous current and potential uses in applications where high temperature strength, hardness, and wear resistance are required often in corrosive environments. These materials are, however, highly anisotropic and brittle, so that their mechanical behavior is often unpredictable. The further development of these materials will require a better understanding of the basic mechanisms controlling deformation, wear, and fracture.The purpose of this talk is to describe applications of TEM to the study of the deformation, wear, and fracture of Al2O3. Similar studies are currently being conducted on SiC and the techniques involved should be applicable to a wide range of hard, brittle materials.

The stability of dislocation networks under various oxygen-doping conditions in superconducting Bi2Sr2CaCu2Oy single crystals and their influence on the flux pinning properties

1994 ◽  
Vol 52 ◽  
pp. 802-803
Author(s):  
Y. Feng ◽  
X. Y. Cai ◽  
R. J. Kelley ◽  
D. C. Larbalestier
Keyword(s):  
Single Crystals ◽  
Oxygen Content ◽  
Basal Plane ◽  
Flux Pinning ◽  
Pinning Centers ◽  
Before And After ◽  
Anomalous Peak ◽  
Basal Plane Dislocation ◽  
The Stability ◽  
Further Development

The issue of strong flux pinning is crucial to the further development of high critical current density Bi-Sr-Ca-Cu-O (BSCCO) superconductors in conductor-like applications, yet the pinning mechanisms are still much debated. Anomalous peaks in the M-H (magnetization vs. magnetic field) loops are commonly observed in Bi2Sr2CaCu2Oy (Bi-2212) single crystals. Oxygen vacancies may be effective flux pinning centers in BSCCO, as has been found in YBCO. However, it has also been proposed that basal-plane dislocation networks also act as effective pinning centers. Yang et al. proposed that the characteristic scale of the basal-plane dislocation networksmay strongly depend on oxygen content and the anomalous peak in the M-H loop at ˜20-30K may be due tothe flux pinning of decoupled two-dimensional pancake vortices by the dislocation networks. In light of this, we have performed an insitu observation on the dislocation networks precisely at the same region before and after annealing in air, vacuumand oxygen, in order to verify whether the dislocation networks change with varying oxygen content Inall cases, we have not found any noticeable changes in dislocation structure, regardless of the drastic changes in Tc and the anomalous magnetization. Therefore, it does not appear that the anomalous peak in the M-H loops is controlled by the basal-plane dislocation networks.

Electron microscopy study of shock synthesis of silicides

1993 ◽  
Vol 51 ◽  
pp. 1162-1163
Author(s):  
Kenneth S. Vecchio
Keyword(s):  
Shock Wave ◽  
Plastic Deformation ◽  
Close Contact ◽  
Microscopy Study ◽  
High Energy ◽  
Electron Microscopy Study ◽  
Powder Materials ◽  
Porous Powder ◽  
Wave Effects ◽  
Wave Passage

Shock-induced reactions (or shock synthesis) have been studied since the 1960’s but are still poorly understood, partly due to the fact that the reaction kinetics are very fast making experimental analysis of the reaction difficult. Shock synthesis is closely related to combustion synthesis, and occurs in the same systems that undergo exothermic gasless combustion reactions. The thermite reaction (Fe2O3 + 2Al -> 2Fe + Al2O3) is prototypical of this class of reactions. The effects of shock-wave passage through porous (powder) materials are complex, because intense and non-uniform plastic deformation is coupled with the shock-wave effects. Thus, the particle interiors experience primarily the effects of shock waves, while the surfaces undergo intense plastic deformation which can often result in interfacial melting. Shock synthesis of compounds from powders is triggered by the extraordinarily high energy deposition rate at the surfaces of the powders, forcing them in close contact, activating them by introducing defects, and heating them close to or even above their melting temperatures.

Perceived Burden of Informal Caregivers of a Chronically Ill Older Family Member

GeroPsych ◽  
2011 ◽  
Vol 24 (3) ◽  
pp. 143-154 ◽  
Author(s):  
Elmar Gräßel ◽  
Raffaela Adabbo
Keyword(s):  
Family Member ◽  
Informal Caregiver ◽  
Chronically Ill ◽  
Stress Model ◽  
The Past ◽  
Perceived Burden ◽  
Hypothetical Construct ◽  
Care Situation ◽  
The Impact ◽  
Further Development

The burden of caregivers has been intensively researched for the past 30 years and has resulted in a multitude of individual findings. This review illustrates the significance of the hypothetical construct of perceived burden for the further development and design of the homecare situation. Following explanations regarding the term informal caregiver, we derive the construct burden from its conceptual association with the transactional stress model of Lazarus and Folkman. Once the extent and characteristics of burden have been set forth, we then present the impact of perceived burden as the care situation. The question of predictors of burden will lead into the last section from which implications can be derived for homecare and relief of caregivers.

Cognitive Health Counseling 40+

2013 ◽  
Vol 21 (1) ◽  
pp. 24-33 ◽  
Author(s):  
Anne Eschen ◽  
Franzisca Zehnder ◽  
Mike Martin
Keyword(s):  
Outcome Variable ◽  
Pilot Phase ◽  
Subjective Memory ◽  
Cognitive Health ◽  
Health Counseling ◽  
Agents Of Change ◽  
Main Outcome Variable ◽  
Further Development

This article introduces Cognitive Health Counseling 40+ (CH.CO40+), an individualized intervention that is conceptually based on the orchestration model of quality-of-life management ( Martin & Kliegel, 2010 ) and aims at improving satisfaction with cognitive health in adults aged 40 years and older. We describe the theoretically deduced characteristics of CH.CO40+, its target group, its multifactorial nature, its individualization, the application of subjective and objective measures, the role of participants as agents of change, and the rationale for choosing participants’ satisfaction with their cognitive health as main outcome variable. A pilot phase with 15 middle-aged and six older adults suggests that CH.CO40+ attracts, and may be particularly suitable for, subjective memory complainers. Implications of the pilot data for the further development of the intervention are discussed.

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