Browsing by Author "Pavlovskyy, Yuriy"

Now showing 1 - 2 of 2

Laser surface modification of materials
(Lviv Politechnic Publishing House, 2021) Pavlovskyy, Yuriy; Ivan Franko Drohobych State Pedagogical University
To develop any process of laser technology, you need to solve 3 problems: 1) What are the properties of the interaction of laser radiation with matter must be selected to achieve the goal (resonant – non-resonant, absorption-scattering, photo- or thermal absorption, heating, hardening, melting, softening, evaporation, decomposition, coagulation, etc.); 2) What type of laser source should be used to achieve this goal (wavelength, operation mode – continuous or pulse frequency, power, pulse duration, transverse energy distribution in the beam, coherence, monochromaticity, polarization, etc. taking into account the reliability, stability of the process and its value, and how to calculate and verify these parameters ?; 3) What are the requirements for the transverse and longitudinal shape of the beam and what opto-mechanical, opto-electronic and other systems are needed to solve this problem? Successful solution of these problems hardens the high quality of the result of the application of laser technology of materials processing. The aim of this work is to show the effectiveness of laser surface treatment of materials on their micromechanical properties. The surface of the samples was treated with laser radiation using a pulsed neodymium laser YAG: Nd. Vickers microhardness measurements were then performed. The surface of silicon carbide was irradiated with a laser beam with different technical parameters. The micromechanical characteristics of the treated samples were studied and their comparison with the source material was made. Suggestions for laser modification of mechanical properties of superhard materials are made. Alloying of aluminum with titanium nitride impurities by pulsed laser irradiation was performed. A significant increase in microhardness in the field of laser fusion of titanium nitride nanopowder into the aluminum matrix was revealed. We have thus shown that laser treatment of structural and functional materials is an effective method of controlling their properties. A set of experimental studies, in particular, structural, optical, and magnetic, will be conducted to physically substantiate the established results. In this paper, we have expressed our views, citing well-known literature sources.
Micromechanical properties and thermal annealing of zinc oxide bulk ceramic
(Publishing House of Lviv Polytechnic National University, 2015) Virt, Ihor; Pavlovskyy, Yuriy; Hadzaman, Ivan
Zinc oxide has numerous commercial device applications. Polycrystalline ZnO varistors, for example, are widely used in high voltage and power-related applications in industries such as microelectronics. One of the ways to control the properties of ZnO is its annealing in various environments, including oxygen, which leads to increased hardness and fracture toughness of ceramics. Therefore, the study of micromechanical properties of materials for modern electronics is an important and vital issue, both in terms of technology for improving quality of the final product and from the point of view of prospect of its practical use. The structural properties of the ceramic samples of ZnO have been studied. The average grain size has been defined. The micromechanical properties have been studied. The temperature conditions of increasing microhardness of ZnO have been defined after annealing in an oxygen atmosphere.