On an approach to constructing a scientific knowledge management information system for the subject domain “Superhard Materials”

The paper addresses an approach to constructing an information system for management of scientific knowledge presented in the form of electronic documents of various types. The approach is based on the heuristic pattern-recognition method. The authors describe an algorithm for automatic document classification by research areas in the subject domain “Superhard Materials”.     

Application of acoustic methods for the monitoring of products made of hard alloys

A system for the ultrasonic (US) control of large hard alloy articles developed in the Institute of Superhard Materials of the Ukrainian National Academy of Sciences is described. Ultrasonic control detects defects with a size from 0.3 mm in the sintering stage, which substantially reduced the number of damages in critical friction units. We investigate the influence of the structure on the sound velocity, modulus of elasticity, and damping properties of VK6 and VK8 hard alloys supplied by different producers.     

High-pressure apparatuses in production of synthetic diamonds (Review)

Brief information is given about the development of high-pressure apparatuses starting in the thirties of the last century. The devices developed by the members of the Bakul Institute for Superhard Materials, National Academy of Sciences of Ukraine, in the second half of the 20th century are discussed in more detail.     

Manufacture of tips for diamond burnishing and dressing probes for abrasive wheels with a diamond composition thermal material AKTM®

A thermally sound composite material, consisting of polycrystalline diamond and silicon carbide, namely the AKTM® aggregate, was developed at the Institute for Superhard Materials of the National Academy of Ukraine. Its improved physical and mechanical properties make it suitable for a wide range of material removal operations. In the present paper the manufacture and the performance of the material on industrial applications are discussed.     

Fractal and information characteristics of the stressed state of a massif and their effect on the process of fracture formation

A probability-information method for describing the stressed state of a massif is developed. An analysis of the interrelationship of massif fracturing, the shape of the tool, and the stressed state of the massif in loading is made, and the dependence between the information characteristics of these distributions is found.Institute of Superhard Materials, Academy of Sciences of the Ukraine, Kiev. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 67, Nos. 1–2, pp. 73–77, July–August, 1994.     

On the Achievements of the Bakul Institute for Superhard Materials in the Field of Synthesis and Sintering of Superhard Materialsfor the Period of the Activity in the Composition of the National Academy of Science of Ukraine

Basic achievements of the Bakul Institute for Superhard Materials in the field of synthesis and sintering of superhard materials at extremely high p-T parameters while being in the composition of the National Academy of Science of Ukraine are presented.     

Thermal conductivity of a composite material reinforced by regularly distributed spheroidal particles

A rigorous solution of the problem of determining the effective thermal conductivity tensor of a composite material with regularly distributed spheroidal interstitials is presented.Institute of Superhard Materials, Academy of Sciences of Ukraine, Kiev, Ukraine. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 66, No. 4, pp. 497–504, April, 1994.     

High-strength state of two-phase composite materials part 2. Cermets

Numerical simulation of the cooling process was carried out to determine the residual stress-strain state of diamond-bearing and tungsten-cobalt hard alloys after sintering. The results show that the thermal stresses of these materials increase their tensile strength. The concentration dependence of the tensile strength of alloys of the WC-Co system is analyzed.Translated from Problemy Prochnosti, No. 3, pp. 17–24, March, 1991.The authors are grateful to M. G. Loshak, senior scientific worker of the Institute of Superhard Materials of the Academy of Sciences of the Ukrainian SSR, for fruitful cooperation and supplying the photograph of the microstructure of the hard alloy.     

Assessment of conventional elastic limit for a hard WC-Co alloy in compression

This paper presents an algorithm for the calculation of a conventional elastic limit for the alloy WC-Co in compression considering residual thermal stresses in its phases. The algorithm is based on equations of thermoelasticity for two-phase composite materials. Comparison of the theoretical and experimental results show their fair agreement. Institute of Superhard Materials, National Academy of Sciences of Ukraine, Kiev, Ukraine. Translated from Problemy Prochnosti, No. 1, pp. 111–119, January–February, 2000.     

Assessment of conventional elastic limit for a hard WC-Co alloy in tension

This paper presents an algorithm for the calculation of a conventional elastic limit for WC-Co alloy in tension considering residual thermal stresses in its phases. The algorithm is based on equations of thermoelasticity for two-phase composite materials. Comparison of theoretical and experimental results revealed their fair agreement. Residual thermal stresses were found to have an appreciable effect on the elastic limit of a hard alloy in tension. Institute of Superhard Materials, National Academy of Sciences of Ukraine, Kiev, Ukraine. Translated from Problemy Prochnosti, No. 6, pp. 116–122, November–December, 1999.     

Structural strength of the hard-faced working components of deforming pull broaches

A numerical method of estimating the structural strength of the working components of deforming pull broaches, which is based on use of the finite-element method for determination of the stress-strain state (SSS) and a nonlocal strength criterion, is developed. The dependence of deforming components operating under a complex stress state with allowance for scale effect and nonuniformity of stress state on the loading conditions and geometry of the tool (component height, length of contact, wall thickness, slope of generatrix of the effective cone) is evaluated. It is established, among other things, that the slope of the generatrix of the effective cone of the deforming component fails to affect if strength when the height of the component and the extent of the load application are constant. The software package “Uprugost'-2,” which was developed by the Institute of Superhard Materials, National Academy of Sciences of the Ukraine, is used to determine the SSS of the working components of deforming pull broaches. Translated from Problemy Prochnosti, No. 12, pp. 62–68, December, 1994.     

Large elastoplastic strains and the stressed state of a deformable gasket in high pressure equipment with diamond anvils

A procedure is developed and realized in the form of a numerical modelling program for deformation of a gasket in diamond anvils taking account of the effect of high pressure and large elastoplastic strains for the material. The procedure is based on the finite element method with a stepwise iteration algorithm (the initial stress method). In the case of considerable distortion of the finite element network with large strains a procedure is used for redefining the network deformation. A package of programs for solving elastoplastic problems with large strains and high pressure developed at the Institute of Superhard Materials of the Ukrainian National Academy of Sciences is used in the calculations. Two materials are considered: hardened stainless steel T301 and pressed lithographic limestone (PLL). A degree of compression of a factor of eight is achieved for PLL (Odquist parameter q5.5, elastic volumetric strain (EVS) 0.7, pressure 24 GPa) and a factor of 5.8 for steel T301 (q3, EVS 0.7, pressure 50 GPa). The distribution of elastic and plastic zones during deformation and stress distribution over the anvil-gasket contact surface are obtained, and the stagewise nature of the deformation process is revealed.Translated from Problemy Prochnosti, No. 3, pp. 78–87, March, 1996.     

Plasticity of diamond at room temperature and determination of its hardness using an atomic force microscope with an ultrahard C60 fullerite tip

A method has been developed to measure the hardness of superhard materials with an atomic force microscope. By using an indenter made of ultrahard fullerite C₆₀, of hardness superior to that of diamond, plastic deformation of diamond is achieved at room temperature without any crack formation and its hardness is measured. “Superhard Materials” Scientific and Technical Center, State Committee for Science and Technology Pis’ma Zh. Tekh. Fiz. 23, 25–29 (July 26, 1997)     

Comparative estimation of mechanical properties of cemented carbides by the kinetics of penetration of a rigid punch under contact cyclic loading

We suggest a method of contact fatigue testing of cemented carbides. It involves cyclic loading of a specimen (half-space) with a flat circular punch by a pulsating compressive stress. Both the loading punch and the test specimens are made of cemented carbides. It is found that the parameters of contact fatigue of a cemented carbide include the depth of the punch penetration into the specimen, σ, after a given number of cycles, the form of the dependence of the penetration depth on the number of cycles, the number of loading cycles between abrupt changes in the growth of the σ values, and the number of these changes. With these parameters determined by laboratory tests on small specimens, we can predict the durability of large carbide components subjected in operation to contact cyclic loads. V. N. Bakul Institute for Superhard Materials, National Academy of Sciences of Ukraine, Kiev, Ukraine. Translated from Problemy Prochnosti, No. 3, pp. 28–37, May–June, 1998.     

Integrated system of databases on the properties of inorganic substances and materials

An integrated system of databases on the properties of inorganic substances and materials has been developed, currently combining the database of the A.A. Baikov Institute of Metallurgy and Materials Science, Russian Academy of Sciences, and an AtomWork database on the properties of inorganic substances, developed at the National Institute for Materials Science (Japan). This system is developed as an information service for specialists and for computer-aided design of new inorganic compounds, which was supported by an elaborate information-analytical system. The results of application of this system for compound design that have not yet been synthesized are presented.     

纳米复合超硬薄膜的研究现状

自1994年Veprek等人提出纳米复合超硬薄膜的概念以来,以其优异的力学性能和化学性能而成为当今材料科学领域的研究热点之一.本文将介绍纳米复合超硬薄膜的概念、设计思想、超硬机制、制备技术及工艺、性能和应用前景,及其发展趋势.     

Superharter Kohlenstoff abgeschieden mit gepulstem Hochstrombogen als Nanoschutzschicht f�r Magnetspeicherplatten

Superhard amorphous Carbon films (ta‐C) deposited by pulsed High‐Current Arc (HCA) possess a good perspective to be used as future ultrathin protective coatings for magnetic hard disks. The ta‐C coatings meet all demands concerning the mechanical, chemical and tribological properties required for corrosion and wear protective coatings with thicknesses of 2‐3nm. From the current point of view the deposition technique also qualifies for an industrial mass production. Consequently there is a very good prospect that in near future the High‐Current Arc technique will be the method of choice for Carbon deposition in industrial hard disk drive production.     

Mechanical Characteristics of 26H2MF and St12T Steels under Compression at Elevated Temperatures

Strength of Materials - A system for recording the contraction of cylindrical specimens under static compression loading was developed based on the original cantilever-type extensometer and the...     

面向绿色制造的材料选择研究

面向绿色制造的材料选择较之传统材料选择是一种全新的理念和思路.研究了材料对外部环境的影响,提出了面向绿色制造的材料选择方法:技术性原则、经济性原则和环境性原则的综合和集成,探讨了绿色材料数据库和知识库、绿色材料生命周期环境影响评估系统等支撑技术,构建了面向绿色制造的材料选择多目标决策模型,以便为材料选择提供理论和技术支持.     

公式类知识管理系统的研究与开发

介绍了现今的知识管理思想及企业知识资源分类方法，分析了工程知识库管理系统的主要特点以及存在的不足。针对产品设计活动中应用知识的特点，采用面向对象方法来描述公式类型的知识，开发了一个通用的公式类知识管理系统。该系统不仅能够方便用户直接对公式类型知识进行操作、管理和维护，同时也可以为不同的智能系统提供统一的接口。