Table of Contents



    • The influence of galvanic coatings as a chemical pretreatment of the surface on the microgeometry of steel materials

      pg(s) 85-87

      In the contribution, the surface quality of the steel substrate is analyzed from the point of view of its microgeometry as a set of quantities capturing the differences of individual surface changes. The subject of investigation are the surfaces of steel substrates, i.e. the base material, degreased surface, standard galvanized surface, surface after galvanizing and subsequent chromating, surface after phosphating and surface after phosphating and application of RAL coating.

    • Additive technologies applying in the design, development and filtering materials manufacturing

      pg(s) 88-90

      On the filter for fine air purification example the possibilities of additive technologies are shown, which allow to simplify and facilitate significantly the product development process, in particular, the filtering purpose. The results of 3-D modeling of the filter design, as well as 3-D modeling and 3-D printing of the tooling for studying the properties of filter elements to the filter and their structural elements (except for the filter layer) are given. The possibility of questions operative solution in case of adjustment necessity of tooling designs and filter elements at additive technologies application is noted.

    • Surface treatment by laser cladding

      pg(s) 91-93

      The paper presents the results of a research focused on the application of laser surfacing of functional surfaces using an additve material in the form of a wire. Cladding is made in a single layer using a robot. The quality of the cladding layer was evaluated by ultrasonic inspection. Possible occurrence of internal defects was assessed. Macrostructures and microstructures were analyzed on metallographic sections using light microscopy. Influence of the used additive material and the cladding parameters on the microhardness behaviour in the individual parts of the test specimens was also evaluated.

    • Experimental self-cleaning glass coatings for photovoltaic systems placed in a real environment

      pg(s) 94-96

      Experimental vitreous samples with the presence of self-cleaning coatings applied by the sol-gel method were selected, which were tested in a real environment under cyclic atmospheric conditions in different TPPs / TPP-Sofia and TPP-Republika, Pernik/. The resulting thin films were studied by UV-NIS – VIR spectroscopy, AFM, contact angle, etc. The experimental samples are potentially applicable in the operation of photovoltaic panels with increased efficiency and sustainability in the conditions of an industrial environment and under the influence of various meteorological factors.

    • From 3D scanning, reverse engineering to real part production of personalized car parts

      pg(s) 97-99

      In personalized mechanical parts production, an important issue is the functionality of the part itself in the chain of multi assembled parts. There are cases when same custom parts need to be produced by fulfilling the solution of connecting two or more elements together and creating a functional mechanical system. Personalized components that are going to feet in between two existing and functional element or systems are difficult to be produced. These difficulty in terms of mechanical solutions means, dimensional accuracy tolerances of the new part and real existing features parts. By creating these personalized middle nodes which will connect two existing elements the precision accuracy feature, like tolerances, is very important. The challenges are bigger when dealing with maximum lifespan performance while withstanding mechanical shock and minimizing fatigue destruction problems. Reducing such a challenging task the 3D scanners and reverse engineering workflow fill the gap by increasing precision and accuracy tolerances digitalization’s of existing parts, creating the reverse counterpart, and reducing time to market. In our work we show a full workflow from non-contact 3D scans, reverse engineering process, for CNC aluminium milling of the digitized part in a real application sector such as modified car application. This attempt will show the benefits of active 3D scanner by surpassing some challenges such as metallic surface reflection problem that arises during scan. In the end the entire process gives to the user all the detailed technical documentation including drawings, materials, and manufacturing instructions.

    • Investigation of composite building elements in a real environment

      pg(s) 100-104

      A study was carried out on the incorporation in a real enirontment of fabricated innovative building elements. The investigated elements include products such as rectangular plates, “П” and semi “O” shaped elements, all made of composite material consisting of spherical foam glass granules bonded with a suitable multi-component cement mixture and manufactured by a specially developed technology. The elements have a specific shape, dimensions and particular physical and mechanical characteristics, thermal and acoustic insulation properties and fire-resistant qualities. The aim of the study is to incorporate them into given construction objects, mainly buildings, and to determine the efficiency and efficacy of the process of incorporating the building elements into a real building structure


    • The impact of particle size on mechanical-acoustic properties of cenosphere powders

      pg(s) 105-108

      Cenospheres are used in a variety of applications, including as fillers in building, construction, plastic, and composite materials. The aim of this paper is to evaluate the effect of particle size on the mechanical-acoustic properties of cenosphere powders, which were produced in two different sizes. The mechanical-acoustic properties of the studied powders were experimentally determined based on the frequency dependencies of the sound absorption coefficient, using the transfer function method. It can be concluded that not only particle size, but also powder bed height and the excitation frequency of acoustic waves, significantly influenced the mechanical-acoustic properties of the studied cenospheres.

    • Environmentally friendly nanoscale modifiers for polymer matrices

      pg(s) 109-110

      The article presents the results of studies of the structure and properties of nanodispersed silicon carbide particles using the method of infrared spectroscopy of disturbed total internal reflection, as well as electret thermal analysis. Temperature ranges of the occurrence of TST in the polymer matrix have been established, which may be due to the processes of melting and oxidation of the polymer matrix, accompanied by the release of charge carriers. The activity of silicate-containing particles used to modify polymer matrices has been analyzed. It has been shown that the introduction of SiC particles into the polymer increases the intensity of TST peaks. The prospects of using ultrafine SiC particles obtained from natural raw materials for the modification of polymer materials are considered.