Evolution of surface defects in platinum alloy wire under drawing

The shape and chemical composition of particles polluting the surface of ultrafine wire made of the platinum Pt92.5Pd4Rh3.5 alloy has been revealed by electron microscopy and microspectral analysis. The phenomenon of the appearance of pores in the particles, which are elongated in the direction of drawing, has been discovered. The problem of calculating the stress-strain state is stated by the finite element method. After solving the problem, it is demonstrated that the appearance of additional defects is related to the proportion of stresses in the scheme of metal forming by drawing. © 2017 Author(s).The work was done within the State Task, theme No. 01201375904, and financially supported by the RF Government, No. 211 (contract No. 02.A03.21.0006)

DISPERSION CHARACTERISTICS OF GOLD WIRE RELATIVE DECREASE

Measurements of the relative narrowing of gold wire Zl 99.99 along the route of drawing are made. The presence of a decrease in the level of plasticity with a gradual increase in this value was observed with further thinning of the wire. The minimum point corresponds approximately to the point of dispersion maximum. A hypothesis is advanced on the development of the process of softening when the critical degree of deformation is accumulated.Выполнены измерения относительного сужения золотой проволоки Зл 99,99 по маршруту волочения. Выявлено наличие понижения уровня пластичности с постепенным увеличением этой величины при дальнейшем утонении проволоки. Точка минимума соответствует примерно точке максимума дисперсии. Высказана гипотеза о развитии процесса разупрочнения при накоплении критической степени деформации

PLASTIC DEFORMATIONS IN THE SILVER WIRE SCALPING

Выполнены измерения микротвердости скальпированной проволоки из серебра. Показана интенсивность прироста микротвердости по мере съема слоев, что говорит о проникновении пластической деформации в приповерхностные слои заготовки. Сделан прогноз о возможном снижении температуры начала рекристаллизации для этих слоев металла.The microhardness of scalped silver wire is measured. The intensity of the microhardness increment is shown as the layers are removed, which indicates the penetration of plastic deformation into the near-surface layers of the billet. A prognosis is made about a possible decrease in the temperature of the onset of recrystallization for these metal layers

THE STRUCTURAL DEFECTS IN THE PLATINUM WIRE MANUFACTURING PROCESS

Выполнено исследование процессов дефектообразования в технологии производства проволоки из платины марки Пл 2 разных диаметров: 1,2 мм, 60 и 40 мкм. Приведены данные микроспектрального анализа поверхности проволоки, сформулированы причины появления ряда дефектов.The processes of the defects formation were carried in the technology of the wire production from the Pl 2 platinum alloy. There were the different diameters: 1.2 mm, 60 μm and 40 μm. In this article the data of wire surface micro spectral analysis were shown, the reasons of the formation defects were formulated

Revisiting Pushchino RRAT search using neural network

The search for rotating radio transients (RRAT) at declination from -9o to +42o was carried out in the semi-annual monitoring data obtained on the Large Phased Array (LPA) radio telescope at the frequency of 111 MHz. A neural network was used to search for candidates. 4 new RRATs were detected, having dispersion measures (DM) 5-16 pc/cm3. A comparison with an earlier RRAT search conducted using the same data shows that the neural network reduced the amount of interference by 80 times, down to 1.3% of the initial amount of interferences. The loss of real pulsar pulses does not exceed 6% of their total number.Comment: 7 pages, 2 figures, submitted to A&

«RAPID-2D» modelling of stress states of the workpiece during the drawing steps

The modeling of the workpiece stress state was carried out on the drawing steps by the plastic deformation analysis of «RAPID-2D». It was conclude that there is opportunity of the fracture localization near periphery or in the center of the workpiece depending on the stress state.Выполнено моделирование напряженного состояния заготовки по переходам волочения с помощью системы анализа пластического формоизменения «РАПИД-2D». Сделан вывод о возможности локализации разрушения на периферии или в центре заготовки в зависимости от схемы напряженного состояния