Investigation the structure and properties of deformed semi-finished products produced from chips of Al–Mg alloys system alloyed with scandium

The article presents the results of studies that make it possible to solve the problem of processing secondary waste from expensive aluminum alloys without irretrievable loss of metal. For this purpose, tasks were set and solved for the development of technological schemes for obtaining longish deformed semi-finished products from chip waste of Al–Mg alloys 01570 and 1580 alloyed with scandium using methods of powder metallurgy and metal forming. For their experimental verification, the operations of chip briquetting, combined rolling-extrusion (continuous extrusion), sectional rolling, hot extrusion and drawing in combination with heat treatment were applied. According to these schemes, semi-finished products in the form of rods and wires were obtained. Structure and mechanical properties were investigated. It has been revealed that when hot-extruded rods are obtained from chip briquettes of alloy 01570 on a vertical hydraulic press, even with significant degrees of deformation during extrusion, the margin of plastic properties is small and makes it possible to obtain a wire with a diameter of only 4.2 mm after drawing. The processing of briquettes from 1580 alloy chips using the combined rolling-extrusion method makes it possible to obtain after cold deformation a wire with a diameter of up to 3 mm. At the same time, the influence of the annealing process on the structure and properties of deformed semi-finished products from the investigated alloys was studied. It is shown that due to the low plasticity of the investigated material cold working of the rods must be carried out with small degrees of deformation, alternating it with intermediate annealing according to the proposed regime. An analysis of the physical and mechanical properties of the wire obtained using combined processing showed that its strength and plastic properties are comparable to the properties of the wire obtained from a cast billet, and the structure is characterized by a high degree of elaboration and compactness. Thus, as a result of the research, technological schemes have been developed and processing parameters have been determined for the production of rods and wire from graded chip waste of alloys 01570 and 1580 using compaction, discrete and continuous extrusion, as well as cold drawing. © 2022 The AuthorsMinistry of Education and Science of the Russian Federation, Minobrnauka: FSRZ-2020-0013The research was carried out within the framework of the state assignment of the Ministry of Science and Higher Education of the Russian Federation (scientific theme code FSRZ-2020-0013)

Explaining varieties of corruption in the Afghan justice sector

© 2015 Taylor & Francis. Judicial reform in Afghanistan is seriously undermined by systemic corruption that has resulted in low legitimacy of the state and weak rule of law. This article reviews the main shortcomings in the Afghan justice system with reference to 70 interviews conducted in Kabul. Building on legal pluralism and a political economic approach, the shortcomings and causes and consequences of corruption in the Afghan justice sector are highlighted. These range from low pay, resulting in bribery; criminal and political intrusion into the judiciary; non-adherence to meritocracy, with poorly educated judges and prosecutors; and low funding in the judicial sector resulting in weak case tracking and human rights abuses in the countryside. This is followed by sociological approaches: understanding corruption from a non-Western approach and emphasis on religion, morality and ethics in order to curb it

Магнитно-резонансная диагностика жидкостных скоплений при остром интерстициальном панкреатите

The article analyses MR examinations of 160 patients with interstitial acute pancreatitis, in absence of MR signs of necrosis of pancreatic parenchyma; the incidence of fluid collections and their outcomes are estimated. Small single fluid collections in the first day after an attack of acute pancreatitis were revealed in 27.5% of cases, multiple and large fluid collections without signs of parenchymal necrosis were revealed in 15.6%. Follow-up MR examinations showed full resolution of peripancreatic fluid collections in 78.7% of cases. Resistant unencapsulated and partially encapsulated collections were found in 7 of 47 patients (14.9%). Local complications requiring surgical intervention developed exclusively in patients with fluid collections and amounted to 1.9% of the whole group of 160 patients, and 6.4% of patients with acute pancreatitis without signs of necrosis of pancreas and peripancreatic fat, but with fluid collections.The authors came to the conclusion that routine MR examinations of patients with interstitial acute pancreatitis were indicated for patients with fluid collections to estimate the dynamics of changes (resolution of collections or development of complications).В статье проанализированы магнитно-резонансные (МР) исследования 160 пациентов с легкой формой острого панкреатита при отсутствии МР-признаков некроза паренхимы поджелудочной железы, оценена частота жидкостных скоплений и их исходы. Одиночные, небольших размеров жидкостные скопления в первые сутки после атаки острого панкреатита выявлены в 27,5% случаев, множественные и большие скопления жидкости выявлены в 15,6%. Контрольные МР-исследования показали полное рассасывание ретроперитонеальных скоплений жидкости в 78,7% случаев. Стойкие неинкапсулированные и частично инкапсулированные скопления определены у 7 (14,9%) пациентов из 47. Локальные осложнения, потребовавшие хирургического вмешательства, развились исключительно у пациентов с жидкостными скоплениями, и составили 1,9% на всю группу, а у больных с жидкостными скоплениями — 6,4%.Авторы исследования пришли к выводу, что стандартные МР-исследования у пациентов с легкими интерстициальными формами острого панкреатита показаны больным со скоплениями жидкости для определения динамики развития изменений (рассасывание или развитие осложнений)

Damage criterion comparison at unidirectional and alternating torsion of samples

The paper presents the results of the analysis of computer simulation of unidirectional and alternating torsion of cylindrical samples in the software complex Deform 3D. The accumulated deformation degree and damage criterion were taken as compared parameters. Damage was calculated by two existing methods: Cockroft-Latham and Bogatov methods. The results of the analysis show that the proposed method for determining the damage criterion is more accurate when testing samples for alternating twisting than the most currently used method since it takes into account the number of loading stages and the plastic deformation amplitude. © Published under licence by IOP Publishing Ltd.BVD PECE spol. s r.o.;CSNMT;DynaWeld;EDAX;et al.;Linsei

EXPERIMENTAL STUDY ON POWER PARAMETERS OF “ROLLING - ECA-PRESSING” COMBINED PROCESS

Introduction.  Power  parameters  of  the  “rolling  −  equalchannel angular pressing” (ECA) combined process are studied. The work objective is to determine forces of rolling and pressing in the deformation by the combined method.Materials and Methods. The die strength calculation and the experiment on deformation of AISI 6063 aluminum samples were carried out. During the experiment, the force values were recorded using a strain-gauge station.Research Results. The strength analysis results show that this die design is suitable for creating an experimental stand of the “rolling − ECA-pressing” combined process, since the calculated  safety  margin  is  sufficient  to  implement  the  pressing under extreme conditions. The rolling forces at all stages of the  deformation  exceed  the  corresponding  pressing  forces, which is a necessary condition for the combined process. Discussion and Conclusions. The obtained results can be used in the design of experimental stands that implement the investigated combined  process. Herewith, the given  strain-gauge method for studying strength characteristics is suitable for the case of calibrated rolls

The effect of cross rolling on the microstructure of ferrous and non-ferrous metals and alloys

The cross rolling is the one of most perspective method of refinement microstructure metals by severe plastic deformation method. This method gives ability to get the long length billets. However, deformation and trajectories of the metal is very heterogeneous across the section of the rolled piece. This paper presents the finite element method (FEM) simulation of hot cross rolling and experimental study of the effect of the cross rolling on a different threeroll mills on the microstructure of ordinary structural alloy steel, stainless steel and technical copper in different zones of the bar. Analysis showed significant structure refinement in all cases. The best result was achieved on the stainless steel, and shown the formation of equal-axis ultra-fine-grain structure on the bar periphery

MR diagnosis of fluid collections in acute interstitial pancreatitis

The article analyses MR examinations of 160 patients with interstitial acute pancreatitis, in absence of MR signs of necrosis of pancreatic parenchyma; the incidence of fluid collections and their outcomes are estimated. Small single fluid collections in the first day after an attack of acute pancreatitis were revealed in 27.5% of cases, multiple and large fluid collections without signs of parenchymal necrosis were revealed in 15.6%. Follow-up MR examinations showed full resolution of peripancreatic fluid collections in 78.7% of cases. Resistant unencapsulated and partially encapsulated collections were found in 7 of 47 patients (14.9%). Local complications requiring surgical intervention developed exclusively in patients with fluid collections and amounted to 1.9% of the whole group of 160 patients, and 6.4% of patients with acute pancreatitis without signs of necrosis of pancreas and peripancreatic fat, but with fluid collections.The authors came to the conclusion that routine MR examinations of patients with interstitial acute pancreatitis were indicated for patients with fluid collections to estimate the dynamics of changes (resolution of collections or development of complications)