Применение моделирования при проектировании инструмента для прессования полых профилей из алюминиевых сплавов

In order to simulate the pressing of hollow profiles made from aluminum alloys, the previously developed design algorithms for the pressing tool and the QForm software were utilized. The objective of this study was to enhance the quality and decrease the design timeintervals for pressing tools used in the industrial production of aluminum alloy profiles. A novel design procedure for a combined tool, along with the technology of semi-continuous pressing with welded hollow profiles made from aluminum alloys, was proposed. This was achieved using the QForm software, which enables efficient calculations and adjustments of pressing parameters and tool geometry through a dialog interface. The developed algorithm and design procedures enable the drawing of hollow profiles, technological calculations of pressing parameters, selection of a suitable horizontal hydraulic press, matrix and splitter design, determination of strength parameters, assessment of equipment load, and preparation of working drawings for the pressing tool. In order to validate the effectiveness of the design procedure, it was applied to typical hollow profiles fabricated on a commercial scale. Two variations of the pressing tool design were examined. Simulation results obtained from QForm Extrusion software, specifically designed for pressing analysis, revealed that the initial design of the tool, with predetermined technological parameters and geometry of the splitter and matrix channels, resulted in uneven flow of profile elements and temperature distribution. However, by adjusting the tool parameters, it was possible to achieve a straight profile exit from the matrix and a uniform temperature distribution across its cross section. Industrial verification of the designed tool, utilizing a 33 MN hydraulic horizontal press for pressing profiles made from alloy 6063, demonstrated that significant modifications to the matrix and splitter were not necessary. By employing the proposed pressing tool design, batches of products were successfully manufactured in compliance with the required technical specifications, while reducing the design time intervals of the pressing tool by approximately 50 %.Для моделирования процесса прессования полых профилей из алюминиевых сплавов использованы разработанные ранее алгоритмы проектирования прессового инструмента и программный комплекс «QForm». Целью проведенных исследований являлось повышение качества и снижение сроков проектирования прессового инструмента для промышленных условий производства профилей из алюминиевых сплавов. Предложены новая методика проектирования комбинированного инструмента и технологии для полунепрерывного прессования со сваркой полых профилей из алюминиевых сплавов с помощью программного комплекса «QForm», который позволяет в диалоговом режиме оперативно проводить многовариантные расчеты с последующей, если необходимо, корректировкой технологических параметров прессования и геометрии инструмента. Созданы алгоритм и процедуры проектирования, которые дают возможность выполнить чертеж полого профиля, осуществить технологические расчеты параметров прессования и выбор горизонтального гидравлического пресса, спроектировать матрицу и рассекатель, провести прочностные расчеты, определить силовую загрузку оборудования и подготовить рабочие чертежи прессового инструмента. Для проверки работоспособности разработанной методики проектирования приведен пример ее реализации для одного из типовых полых профилей, изготавливаемого в промышленном производстве. Рассмотрено проектирование двух вариантов прессового инструмента. С помощью моделирования с использованием программы «QForm Extrusion», предназначенной для анализа процессов прессования, установлено, что первый вариант конструкции инструмента при заданных технологических параметрах и геометрии каналов рассекателя и матрицы приводит к неравномерности истечения различных элементов профиля и температур. В результате проведенной корректировки параметров инструмента удалось добиться прямолинейности выхода профиля из матрицы и равномерности распределения температур по его сечению. Промышленное опробование спроектированного инструмента на гидравлическом горизонтальном прессе с усилием 33 МН для прессования профиля из сплава 6063 показало, что существенной доработки матрицы и рассекателя не требуется. С применением предложенной конструкции прессового инструмента получены партии продукции, соответствующей требованиям действующих технических условий, при этом сроки проектирования прессового инструмента сокращены практически в 2 раза

Pharmaceutical therapy of Q-wave acute myocardial infarction: effects on adrenal morphology and function

Adrenal morphology and function were studied in intensively treated patients with Q-wave acute myocardial infarction (AMI). Adequate analgetic and thrombolytic therapy, as well as beta-adrenoblocker treatment, prevented adrenal medulla depletion. Contralateral adrenal reaction was heterogeneous. The results obtained provide a better understanding of adaptive reactions and medication action mechanisms in intensively treated patients with Q-wave AMI

Research of rolling regimes and mechanical properties of cold-rolled, annealed and welded semi-finished products from experimental alloys of Al-Mg system, economically alloyed by scandium

Текст статьи не публикуется в открытом доступе в соответствии с политикой журнала.Our paper shows the research results of thermodeformation machining of flat ingots made of experimental aluminium alloys, containing magnesium, scandium, rare-earth and transition metals. Relevance of the work aimed at creating the new Al-Mg system alloys, alloyed by scandium, and technologies for obtaining deformed semi-finished products from them using metal forming operations are shown. Regimes of hot and cold sheet rolling for obtaining strips with thickness 1-3 mm from these alloys were calculated and experimentally tested. Experimental research included the following steps: preparation of flat slabs with dimensions 28-150-300 mm for rolling; hot rolling at the temperature of 450 °C with total draw ratio about 6; cold rolling with total draw ratio about 5; annealing of cold-deformed semi-finished products at the temperature of 350 °C within 3 hours; argon-arc welding of the obtained strips along and across the direction of deformation; intergranular corrosion test; evaluation of mechanical properties of the samples. As a result, the nature and degree of corrosion destruction were studied and mechanical properties of deformed, annealed and welded semi-finished products from experimental alloys were determined. It is established that they have a high level of strength and plastic properties of the metal along, across and at an angle 45o relative to the direction of rolling. So tensile strength reaches the value 500-520 MPa for deformed samples, yield strength of metal 435-470 MPa, relative elongation 4.8-6.7%, and for annealed samples the values of the relative elongation increase and can reach 14.0-14.5% at the sufficiently high yield strength 357-369 MPa. Tests for intergranular corrosion of samples after welding showed high corrosion resistance of welded joints. The strength of the welded seam is 0.75-0.85 of the strength of the base metal. The results of research can be recommended for the development of technology for the manufacture of parts from flat products, including welded joints

Combined Endovascular Treatment of Acute Coronary Syndrome with Bioresorbable Scaffolds and Angioplasty in Patient with Critical Lower Limb Ischemia – Hybrid Treatment in Multidisciplinary Hospital

The key to successful treatment in patients with acute coronary syndrome is maximally early revascularization of the coronary arteries. Treatment of multifocal atherosclerosis with lesions of the coronary and peripheral arteries requires coordinated work of the multidisciplinary team of doctors. Critical ischemia of the lower limbs requires urgent revascularization in order to prevent limb amputation. However, it is not always possible to perform revascularization using specialists of the same profile – endovascular or surgical. The use of hybrid methods of treatment (surgical and endovascular) allows to significantly improve the prognosis in saving the limb. The article presents a clinical observation of successful multistep treatment of a patient with acute coronary syndrome in combination with critical ischemia of the lower limb. The first stage was performed by multiple stenting of the coronary arteries with bioabsorptive scaffolds; the second stage was the hybrid treatment – femoral-tibial bypass with simultaneous recanalization and angioplasty of the lower leg arteries with good postoperative and long-term outcome

LONG-TERM RESULTS OF VARIOUS TREATMENT OPTIONS FOR VENTRAL HERNIAS

In modern herniology tension free technic of hernia repair is a leading, thanks mainly to fewer recurrences. However, hernia repair breaks anatomy and functionality of the anterior abdominal wall, which leads to a deterioration in the quality of life of patients. Objective: To analyze the quality of life of patients after hernia repair ventral hernias. Materials and Methods: The analysis of the results of surgical treatment of 199 patients with ventral hernias after hernia repair in 6 months. For the study used questionnaires quality of life using the SF-36 form. Results: characteristics of each operation, positive and negative, are reflected in the indices of physical and mental health of the survey. Conclusions: onlay, inlay methods of hernia repair are characterized by the best indicators of physical health in the late postoperative period. Methods sublayplastics have a greater impact on the health of the patient in the postoperative period. However, mental health indicators surpass a simple hernia repair techniques

Comparative analysis of properties of wires from alloys of Al-REM system, obtained using the methods of continuous extrusion

The article presents the results of experimental studies of the production technology of electrical wire made of aluminum alloy of the Al–REM system with content of rare earth metals in the range of 7-9% using continuous casting and extrusion processing methods. Continuous casting rods with a diameter of 12 mm, obtained by casting into an electromagnetic mold (EMM), were the starting material for research. Methods of continuous extrusion "Conform" and combined rolling-extrusion (CRE) were the main methods to obtain a billet for subsequent drawing. Deformation modes, methods of experiments and equipment for the implementation of two variants of the proposed technology using various methods of continuous extrusion described. At all stages of the technology, samples were taken and the mechanical and electrophysical properties of the obtained deformed semi-finished products (ultimate tensile strength, elongation to failure and electrical resistivity) were studied. Application of the "Conform" method in industrial conditions using standard drawing routes allows obtaining a wire of small diameters with high strength properties, however, the plastic properties and values of electrical resistance do not correspond to the existing requirements of the technical specifications for its production. On the contrary, the plastic properties of hot-extruded rods obtained by the CRE method allow cold deformation using only one intermediate annealing. At the same time, the developed technology using continuous casting, combined rolling-extrusion, drawing modes and final annealing of a wire with a diameter of 0.5 mm provides the required level of plastic and strength properties, as well as minimum values of electrical resistance. The developed modes of deformation and heat treatment can be recommended for the industrial production of electrotechnical wire from high-alloyed Al–REM alloys

Comparative analysis of properties of wires from alloys of Al-REM system, obtained using the methods of continuous extrusion

The article presents the results of experimental studies of the production technology of electrical wire made of aluminum alloy of the Al–REM system with content of rare earth metals in the range of 7-9% using continuous casting and extrusion processing methods. Continuous casting rods with a diameter of 12 mm, obtained by casting into an electromagnetic mold (EMM), were the starting material for research. Methods of continuous extrusion "Conform" and combined rolling-extrusion (CRE) were the main methods to obtain a billet for subsequent drawing. Deformation modes, methods of experiments and equipment for the implementation of two variants of the proposed technology using various methods of continuous extrusion described. At all stages of the technology, samples were taken and the mechanical and electrophysical properties of the obtained deformed semi-finished products (ultimate tensile strength, elongation to failure and electrical resistivity) were studied. Application of the "Conform" method in industrial conditions using standard drawing routes allows obtaining a wire of small diameters with high strength properties, however, the plastic properties and values of electrical resistance do not correspond to the existing requirements of the technical specifications for its production. On the contrary, the plastic properties of hot-extruded rods obtained by the CRE method allow cold deformation using only one intermediate annealing. At the same time, the developed technology using continuous casting, combined rolling-extrusion, drawing modes and final annealing of a wire with a diameter of 0.5 mm provides the required level of plastic and strength properties, as well as minimum values of electrical resistance. The developed modes of deformation and heat treatment can be recommended for the industrial production of electrotechnical wire from high-alloyed Al–REM alloys