The paper describes advances in a promising area for the development of Samsonov’s scientific school at the Igor Sikorsky Kyiv Polytechnic Institute. The main results are provided to refine the mechanisms whereby crystals nucleate and grow from melts of eutectic alloys and acquire their microstructure and phase composition and the mechanisms whereby reinforced composite materials with isotropic and anisotropic microstructure are strengthened for extreme applications involving high-speed heating and cooling, impact interaction, cyclic loading, and corrosive environments. The mechanical properties of reinforced composite materials in a wide temperature range are presented. Areas for application of the reinforced ceramics are identified. [ABSTRACT FROM AUTHOR]
The evolution of knowledge and inventions that contributed to the science of materials has been studied. The development of materials science in the ancient world involved the accumulation of intuitive inventions and the development of crafts. The antiquity established natural philosophy ideas about the nature of matter and divided all existent things into organic and inorganic worlds (Democritus, Epicurus, Aristotle). In the early Middle Ages, alchemy was widespread, with an idea of transmuting elements into gold. Although alchemical ideas were erroneous, they brought some benefits, contributing to the development of scientific experiment. The New Times marked the rapid development of fundamental sciences that promoted theoretical and practical materials science. This paper presents a chronology of the most important inventions and scientific concepts in a tabular form. [ABSTRACT FROM AUTHOR]
The paper examines the production of Si-modified biogenic hydroxyapatite ceramics. The introduction of methylsilicic acid hydrogel in amounts converted to 2 and 5 wt.% Si and subsequent sintering at 600°C increase the specific surface area by 10 times, from 6.1 to 59.8 m/g. The porosity of ceramics increases from 43.0 to 62.3% when the modifying addition reaches up to 5 wt.%, the compressive strength being equal to 27-33 MPa. The modifying addition also influences the structure and reduces the minimum grain size of the material from 0.65 to 0.1μm [ABSTRACT FROM AUTHOR]