Search academic texts

Information × Registration Number 0221U107030, 0120U104958 , R & D reports Title Fundamental aspects of the new materials creation with unique physical, mechanical and radiation properties based on the concentrated multicomponent alloys popup.stage_title Head Tolstolutska Galyna , Доктор фізико-математичних наук Registration Date 26-12-2021 Organization National Science Center "Kharkiv Institute of Physics and Technology" popup.description2 The object of research is the phase-structural state and mechanical properties of multicomponent concentrated alloys (MCCА) in coarse-grained (CG) and nanocrystalline (NC) states. The aim of the work is to study the influence of doping by interstitial atoms on the formation of the structure of cast MCCА, to study the possibility of forming a nanostructured state in these alloys by methods of severe plastic deformation (SPD), to study the mechanical properties of alloys in different structural states. Research methods - metallography, electron microscopy, microanalysis, X - ray diffraction analysis, study of mechanical properties. The effect of carbon on the phase-structural state of MCCA Co25-xCr25Fe25Ni25Cx and oxygen atoms on MCCA TiZrHfNb was experimentally investigated. It was found that the solubility of carbon in the cast alloy Co25-xCr25Fe25Ni25Cx is about 1 at.%. At carbon concentrations x more than 1 at.%, in the interdendritic regions of the alloys a eutectic is formed, consisting of a multicomponent matrix and M7C3 carbides. The SPD of these alloys leads to grain refining to 30-50 nm and a threefold increase in microhardness. It is found that with increasing x in the CG state the microhardness value HV increases monotonically, whereas in the NC state HV is maximal at x=1. The dependence of HV on the temperature in the region of 300-77 K for CG and NC alloys was studied, and the different course of this dependence for NC alloys with different values of x was revealed. An unambiguous relationship between HV and the yield strength of alloys σ0.2 in the entire range of studied temperatures has been established, which allows determining the value of σ0.2 from simple microhardness measurements. The influence of doping with oxygen atoms on the microstructure and mechanical properties of refractory MCCA of the Ti-Zr-Hf-Nb system in the temperature range 77-923 K has been studied. Product Description popup.authors Velykodnyi Oleksii M Rostova Hanna Yu Tikhonovsky Mikhail A popup.nrat_date 2022-03-09 Close