Carbon Friction Pair in Total Hip Replacement

The article examines the advantages of a new pair of friction of the hip joint endoprosthesis made of pyrolytic carbon. The physico-mechanical and tribological characteristics of the material and their comparison with other materials used in the friction pair of hip joint endoprostheses are presented. Information is presented about the making of a material and its strength characteristics and the results of mathematical modeling of a friction pair. The results of a comparative research of the durability between a carbon pair of friction and a ceramic pair of friction

Characterizing the tensile behavior of double wire-feed electron beam additive manufactured "copper-steel" using digital image correlation

The paper presents the results of the evaluation of the mechanical characteristics of samples of multi-metal “copper-steel” structures fabricated by additive double wire electron beam method. The global and local mechanical characteristics were evaluated using uniaxial tensile tests and full-field two-dimensional digital image correlation (DIC) method. DIC revealed the peculiarities of the fracture stages: at the first stage (0.02<ε≤0.08) the formation of V-shaped shear lines occurs; at the second stage (0.08<ε≤0.15) transverse shear lines lead to the formation of a block structure; at the third stage (0.15<ε≤0.21) the plasticity resource ends in the central part of the two necks cracks are formed, and the main crack is the cause of the fracture of the joint. It is found that shear lines are formed first in copper and then propagate to steel. Electron microscopy proves that uniformly distributed iron particles could always be found in the “Fe-Cu” and “Cu-Fe” interfaces. Additionally, the evolution of average strain rates and standard deviations were measured (calculated) in the regions of necks in copper and steel regions. New shear approach shows that the most of angles for parallel shears components are ±45°, rupture angles are about 0°, and combined account of these two types of shears provides us additional discrete angles

Finansowe uwarunkowania decyzji ekonomicznych

Praca recenzowana / peer-reviewed pape

In Situ Investigation of Strain Localization in Sintered, Porous Segmented Alumina

Evaporation of paraffin and ultra-high-molecular-weight polyethylene admixed with alumina powder for the slip casting and sintering process allowed the obtainment of segmented porous alumina ceramics with 50% total porosity, whose deformation behavior we studied. Structurally, these ceramic materials were composed of large and small pores, and a system of discontinuities subdividing the samples into segments. Using digital image correlation (DIC), strain distribution maps were obtained that allowed the observation of strain localization zones, where primary cracks propagated along the interblock discontinuities. Two stages were revealed to be responsible for different mechanisms that provided the sample with damage tolerance under compression loading: the first stage was crack propagation along the block boundaries, which was followed by the second stage of microcracking and fragmentation, consisting of filling of the free spaces with fragments, compaction band generation, and stabilization of the crack. Both stages comprise a cycle that is repeated again and again until the full volume of the sample is occupied by the compaction bands

Investigation peculiarity the visual analysis of imageries during of the inspection certification the apparatus observations

В статье приведены результаты исследования статистических характеристик группы экспертов визуального анализа при выполнении сертификации аппаратуры наблюденияВ статті наведені результати дослідження статистичних характеристик групи експертів візуального аналізу при виконанні сертифікації апаратури спостереженняIn article is coerced research result of the static characteristic group experts of the visual analysis during fulfillment inspection certification of apparatus observation

Evaluation of machine-building enterprises of the Kola Peninsula for developing of the Arctic communications

The research of engineering enterprises with a single and small-batch manufacturing of the Kola Peninsula has been carried out. The possibilities of satisfying demands for their products and services in the regional market have been determined, that is very important for understanding the prospects for the development and exploitation of the Arctic communication

Characterizing the Tensile Behavior of Double Wire-Feed Electron Beam Additive Manufactured &ldquo;Copper&ndash;Steel&rdquo; Using Digital Image Correlation

The paper presents the results of the evaluation of the mechanical characteristics of samples of multi-metal &ldquo;copper-steel&rdquo; structures fabricated by additive double wire electron beam method. The global and local mechanical characteristics were evaluated using uniaxial tensile tests and full-field two-dimensional digital image correlation (DIC) method. DIC revealed the peculiarities of the fracture stages: at the first stage (0.02&lt;&epsilon;&le;0.08) the formation of V-shaped shear lines occurs; at the second stage (0.08&lt;&epsilon;&le;0.15) transverse shear lines lead to the formation of a block structure; at the third stage (0.15&lt;&epsilon;&le;0.21) the plasticity resource ends in the central part of the two necks cracks are formed, and the main crack is the cause of the fracture of the joint. It is found that shear lines are formed first in copper and then propagate to steel. Electron microscopy proves that uniformly distributed iron particles could always be found in the &ldquo;Fe-Cu&rdquo; and &ldquo;Cu-Fe&rdquo; interfaces. Additionally, the evolution of average strain rates and standard deviations were measured (calculated) in the regions of necks in copper and steel regions. New shear approach shows that the most of angles for parallel shears components are &plusmn;45&deg;, rupture angles are about 0&deg;, and combined account of these two types of shears provides us additional discrete angles