ТЕХНОЛОГІЧНІ ВИСОКОЕНТРОПІЙНІ СПЛАВИ — ПЕРСПЕКТИВНИЙ КЛАС КОНСТРУКЦІЙНИХ МАТЕРІАЛІВ: Procesi littâ, 2023, Vol 4 (154), 58-68

• Date: 2023
• Main Authors: Кузнєцова, Т.Л., Бродніковський, Н.П.
• Format: Article
• Language: Ukrainian
• Published: National Academy of Sciences of Ukraine, Physical-Technological Institute of Metals and Alloys of NAS of Ukraine 2023
• Subjects: високоентропійні сплави; особливості кристалізації; жароміцність; технологічність; інтервал кристалізації; дендритна ліквація
• Online Access: https://plit-periodical.org.ua/index.php/plit/article/view/223
• Journal Title: Casting Processes

The physic-chemical prerequisites for the creation of a new promising class of technological construction high-entropy alloys (HEAs) have been established. The precondition for choice of alloy composition are based on the relationship between the atomic and physical properties of alloy elements, characteristic for the creation of high-entropy alloys, the enthalpy of mixing, the alloys composition and state diagrams of alloy components in combination with the crystallization features of alloys, as due by alloying them with components that would contribute to the optimization of technological and thermo physical characteristics of alloys without significant deterioration of specified operational properties, as well as by controlling the formation of fine-crystalline caststructure by thermo physical methods. It is shown that the «entropy» approach proposed by many authors to the construction of a HEAs with given properties cannot solve the problem without selecting a specific qualitative and quantitative physico-chemical combination of alloy elements, taking into account the influence of a large number of factors, primarily technological. Attempts topreserve disordered solid solutions in HEAs due to the increased cooling rate for most HEAs did not yield results, since most HEAs are not technological, characterized by a wide crystallization interval and special thermo physical characteristics (reduced thermal conductivity with increased heat capacity), which do not provide an opportunity to increase the crystallization rate, even at anextremely high cooling rate. For the development of technological HEAs, a method of comprehensive research of the main parameters of the high-entropy technologically alloys is recommended, and the physical and chemical prerequisites for the creation of a new class of HEAs with increased heat strength and heat resistance are determined. The method was experimentally tested at developing of a technological alloy of the Nb-Ti-Al system alloyed with Cr, Zr, Mo, Si, based on the promising HEA.