International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

A novel technology for producing metal powders is presented, the distinctive feature of which are the conditions of forming of powder particles. In particular, under the proposed technology the melt is sucked bottom-up by the vacuum produced by the toroidal vortex of the discharged nucleus of high-pressure water flow in the two-layer cylindrical shell cavity, where it is being dispersed as metallic particles and carried over from the working medium to a special store. The so produced powders have a particular morphology and structure, increased specific surface area and microhardness.

The evaluation of the quality of production process on mechanical properties of reinforcing bars profile 10-32 of steel grade 35GS was performed, obtained in the conditions of the rolling production of JSC “ArcelorMittal Temirtau”. Using a complex quality parameter, the process of rebar production is characterized as stable and controlled.

The main characteristic of the powder metallurgical materials that distinguishes them from the summer ones is the presence in them of residual porosity. For this reason, the processes of their thermochemical treatment are differ significantly from those occurring at saturation of dense ones. In the present paper the impact of technological processes such as boronizing, chromizing, siliconizing, carburizing, borocarburizing, etc., is monitored on the kinetics of diffusion layer growth in powder materials with a porosity of 5÷35%. The specimens of iron powders NC 100.24 and those doped with 2% Cu were subjected to study. The samples were pressed with an effort of 200 ÷ 800MPa and sintered for 0.5h at 1150°C in dissociated NH3 medium. Thermochemical treatment was conducted at 950°C for 4 hours in semi-permeable saturation media. Graphical dependencies for varying the thickness of diffusion coatings in different thermochemical treatment modes are presented, depending on the porosity of the saturation materials.

Because of the combination of high specific strength and excellent corrosion resistance in many media, titanium and titanium alloys are used in aerospace engineering, chemical industry, mechanical engineering etc.
The present work introduces results that demonstrate the effect of the thermal cycle on mechanical properties of Grade 1 Titanium welds, produced by hollow cathode arc discharge in vacuum. Dimensions of the welds were established. The mechanical properties of the welds – hardness and tensile strength – were determined. The influence of the thermal cycle on welds structure was investigated.

Paper presents an overall analytical review of recent achievements in the field of development and improvement of technologies for producing structural materials with ultrafine-grained structure by severe plastic deformation. Main modern methods of obtaining ultrafine-grained structure by severe plastic deformation are described. Special attention to combined process “helical rolling – pressing” is devoted.

The paper deals with a variable multifunctional simulation tool that enables to design and assemble animated models of various technological processes controlled by externally connected fuzzy logic unit. It enables to verify the correctness of fuzzy controller settings in the future control of real technological processes in practice. This tool represents an effective, innovative, and creative concept important to understanding control approach of technological processes modeling as an insight to behavior of real industrial processes and their control which is based on fuzzy logic. On the base of this animated simulation, real technological processes control can be realized successfully according to producer demands afterwards. Models of technological processes assembled by this simulation tool can be then externally controlled by various control strategies (traditional PID controllers, ON-OFF controllers,PLC controllers, fuzzy logic controllers etc.) via a proper real controller connected to the computer. In the paper, two-conveyor-belt system for product packing is shown. The goal consists in control of synchronization of products and boxes placed on individual conveyor belts in order to pack the product into the box. The main concern here is to improve dynamic performance and control efficiency with the help of assembling an animated model of the controlled technological process and its external control by a fuzzy logic unit.

Sustainable transport, as one of the areas on which sustainable development should be founded, depends more and more on introduction of electric vehicles in daily traffic. This paper describes part of the results of wider research related to the analysis of all sustainable transport indicators. Since introduction of electric vehicles is supposed to be done stage by stage in the actual transport, deep understanding of its main parameters/indicators is a prerequisite for reliable analysis. The paper identifies traffic and vehicle structure parameters and rang them in hierarchic order. This structure can serve as substructure in more complex structure of all transport parameters in wider researches.

The project to build a second nuclear power plant in Bulgaria emerged in the 70s of XX century. He repeatedly starts and stops over the past decades, mostly under the influence of external and internal policy decisions. Meanwhile, Bulgarian taxpayers pay large sums for errors and indecision of our political elite. Time specialists in this area say their arguments and take the best decision for Bulgaria instead of wasting money without end.

The paper proposes a methodology for applying three-dimensional laser scanning to obtain an accurate three-dimensional models that will be used to calculate the stress-strain state of constructions of tanks for oil and gas.

In this paper methods of estimating the structural reliability and adequacy of the large industrial enterprises are considered. The combination of the sequential network reduction method and the Newton’s method is proposed for the calculation of structural reliability indices. Estimation of the adequacy is based on the random events simulation by Monte Carlo method.

The range of parameters of the electron beam (density of thermal effect Fn = 7∙106…8∙108 W/m² and travel speeds V = 5∙10-3…5∙10-2 m/s), within which there is an improvement in the performance characteristics of optical elements: increase of microhardness of the surface of elements from optical ceramics from 1,21∙103…2,83∙103MPa to 4,84∙103…7,15∙103 MPa and increase of the spectral transmission coefficient of IR-radiation by 4… 6% for elements of optical glass and for 5… 7% – for elements of optical ceramics; there occurs an increase in the critical values of the external heat flow leading to the destruction of the elements by 1,5…2 times, thus the increase of external pressure up to 107 Pa decreases the specified critical values by 1,3…1,5 times; critical values of thermoelastic stresses in optical elements at heating temperatures 300… 1200 K increase by 1,5…2,5 times, indicating an increase in resistance to thermal effects and increased external pressures of optical elements processed by an electronic beam; the values of critical heights of falling of a steel ball on their surface, leading to destruction of elements, increase from 0,18…1,1 m to 0,37…1,35 m, so, their resistance to mechanical shocks increases. It is established, that increase of durability of optical elements, processed by an electron beam, to external thermal and mechanical effects leads to the increase of probability of non-failure operation of optic-electronic devices under extreme conditions of operation to 10… 20%.