RESUMO
In this paper, we investigated the effect of adding rhenium to Cu-Ni-Si alloys on the mechanical properties and electrical conductivity of these alloys. The scientific objective was to analyze the effect of Re addition on the microstructure of heat- and cold-treated CuNi2Si1 alloys. Transmission electron microscopy (TEM, STEM) and scanning electron microscopy (EDS, WDS) were used to examine the microstructure. Orientation mapping was also performed using a scanning electron microscope (SEM) equipped with a backscattered electron diffraction (EBSD) system. In addition, hardness at low load and conductivity were tested. The obtained results showed that modifying the chemical composition of Re (0.6 wt%) inhibits the recrystallization process in the CuNi2Si1 alloy, which was cold deformed and then subjected to recrystallization annealing.
RESUMO
The influence of the mass concentration of Ag on properties of Cu-Ni alloys is investigated. The effect of silver addition on the structure and properties of Cu-2Ni-1Si alloys is determined. The scientific aim of this research is to determine how the addition of silver affects the mechanisms of strengthening silver-modified supersaturated, deformed, and aged Cu-2Ni-1Si alloys. The applied thermo-derivative analysis has allowed us to determine a range of the temperature values for the beginning and the end of crystallization, the phases and eutectics, and the effects of the modification on the solid fraction of the solidified alloy. In addition to the crystallization kinetics, the microstructure morphology, mechanical properties under real operating conditions, and the electrical conductivity have also been investigated. Moreover, the conducted research includes the impact of heat treatment and plastic deformation on the alloy structure and considers the type, share, and distribution of the intermetallic phases and structural stresses caused by coherent phases, as well as the effect of dislocations in the reinforcing phases during aging. Electron microscopy (SEM), micro-area analysis (EDS), optical microscopy, hardness measurements, and conductivity of the tested alloys are utilized to comment on these properties.
RESUMO
The work examines the effect of rhenium addition on the structure and properties of Cu-2Ni-1Si alloys. The aim of this work was to answer the question of how the addition of rhenium will affect the strengthening mechanisms of rhenium-modified, saturated, plastically deformed and aged Cu-2Ni-1Si alloys. How will this affect the crystallization process? What effect will it have on the properties? Scanning electron microscopy (SEM) and analysis of chemical composition in microareas (energy-dispersive X-ray spectroscopy, EDS), light microscopy, measurements of microhardness and conductivity of the alloys were used for the investigations. Research on chemical and phase composition were carried out with application of transmission electron microscopy (TEM), and scanning transmission electron microscopy (STEM). Modification with rhenium has caused an increase in hardness as a result of precipitation of small phases with rhenium. As the effect of supersaturation, cold plastic treatment as well as aging small phases with rhenium with a size of 200 nm to 600 nm causes both reinforcement of the alloy and makes recrystallization impossible. Re-addition also influences the stabilization of the structure.
