•The effect of Sn on microstructural development of the Ag–Bi–Sn alloys was studied.•Phase transition temperatures were measured.•Density decreases and specific heat capacity increases with ...increasing Sn content.•Temperature variations of thermal diffusivity and thermal conductivity of solid samples were obtained.•Thermal conductivity of solid samples increases with increasing Sn content.
Structural and thermal properties of five Ag–Bi–Sn ternary alloys with tin content ranging from 12.8 to 75.1 mass% and nearly equal mass contents of silver and bismuth were investigated in this study. Microstructures and melting properties of as-solidified alloy samples were examined using scanning electron microscopy with energy dispersive X-ray spectrometry (SEM-EDS), X-ray diffraction (XRD) analysis, and differential thermal analysis (DTA) in combination with the CALPHAD (CALculation of PHase Diagram) method. The observed microconstituents were Ag3Sn, (Sn) and, (Bi) phases as well as ternary (Sn)+(Bi)+Ag3Sn eutectic. The measured temperature of the ternary eutectic reaction was 138.0°C.
The flash method was used for thermal diffusivity measurements in the temperature range from 25 to 100°C. Based on the measured values of thermal diffusivity, thermal conductivity of the solid Ag–Bi–Sn alloys was obtained. Thermal conductivity of the studied Ag–Bi–Sn ternary alloys considerably increases with increasing tin concentration and slightly decreases with increasing temperature.
En este estudio se investigaron las propiedades mecánicas (prueba de dureza Brinell) y eléctricas de algunas aleaciones de Ag-Ge-In ternarias seleccionadas. Los resultados obtenidos para las ...propiedades mecánicas y el análisis ANOVA, se sugiere un modelo matemático de cálculo para las propiedades de cada composición de aleaciones. Las microestructuras de aleaciones se han llevado a cabo mediante microscopía óptica y microscopía electrónica de barrido (SEM). Las fases presentadas en las microestructuras se han detectado mediante análisis de difracción de rayos X (XRD) y las composiciones mediante espectrometría de dispersión de energía (EDS). Los resultados determinados experimentalmente se comparan con los datos calculados. El cálculo de la sección isotérmica a 25 °C se realizó utilizando parámetros termodinámicos optimizados para los sistemas binarios constitutivos. Se obtuvo una buena concordancia general entre los valores experimentales y los calculados.
Microstructure, melting behavior and thermal conductivities of three Bi–Ag alloys with 5, 20 and 45 mass% of Ag were experimentally studied in the present work. Phase morphology of the alloys was ...analyzed by the light microscopy and scanning electron microscopy with energy-dispersive X-ray spectrometry. Phase transition temperatures and their heat effects were measured using differential scanning calorimetry (DSC). The calculation of phase diagrams method was used for the computation of thermodynamic functions such as enthalpy and specific heat capacity of the investigated alloys. Experimentally obtained DSC heating scans were compared with the simulated DSC scans derived from thermodynamic data, and good mutual agreement was noticed. The flash method was used for determination of thermal diffusivity and thermal conductivity of the investigated alloys. It was found that increase in silver content to 45 mass% resulted in modest increase in thermal conductivity of the investigated alloys. Thermal conductivities for all three investigated eutectic alloys slightly decrease with increasing temperature.
The ternary Ge-In-Zn system is chosen for the study due to the importance of germanium-based alloys in the industry of electronic devices and their special application as memory materials. This ...ternary system has not been explored so far. In the current work, experimental techniques such as differential thermal analysis (DTA), scanning electron microscopy (SEM) with energy dispersive spectrometry (EDS), X-ray powder diffraction (XRD)and electrical conductivity tests were used for characterization of the prepared ternary Ge-In-Zn alloys. Investigated alloys were from four isothermal sections at 25, 100, 200 and 300 °C and three vertical sections Ge-InZn, In-GeZn, Zn-GeIn. The obtained results were compared with the results of thermodynamic calculation of phase equilibria based on the Calphad method. The calculation was performed by using thermodynamic parameters for constitutive binary systems. Good agreements between calculated phase diagrams and experimental data have been obtained without introducing ternary thermodynamic parameters. Based on that, calculations of liquidus projection and invariant reactions were performed.
Microstructure, phase transitions and thermal properties including thermal diffusivity and thermal conductivity of four Ag–Ge alloys with 20, 40, 60 and 80 at % of Ge were experimentally investigated ...in this study. Observation and analysis of the alloy microstructures and morphologies of (Ge) phase in the hypereutectic alloys were carried out using optical microscopy and scanning electron microscopy with energy-dispersive X-ray spectrometry (SEM–EDS). Phase transitions of the alloys were studied using differential scanning calorimetry (DSC). Experimentally determined temperature of the eutectic reaction was 650.9 °C. The xenon flash method was used for thermal diffusivity measurements in the temperature range from 25 to 400 °C. Based on the measured values of thermal diffusivity, thermal conductivity of the solid Ag–Ge alloys was determined. It was found that both thermal diffusivity and thermal conductivity show a minimum at 20 at % Ge which is close to the eutectic composition. The obtained results were compared with the results of thermodynamic calculation and literature data, and a close agreement was observed.
Two Cu-Zn-Al alloys with variable content of Zn (25 and 30 wt%) and constant Al content (4 wt%) prepared by induction melting of pure metals and hot rolled into strips of 0.5 mm thickness were ...thermally processed by using three different heat treatments: direct quenching, step-quenching and up-quenching with boiling water and room temperature water as the quenchants. The effects of composition and different methods of heat treatment on the microstructure and transformation temperatures of the investigated Cu-Zn-Al alloys were investigated using SEM-EDS and DSC techniques.
Phase diagram of the Cu-Ge-Sb ternary system has been investigated experimentally and assessed thermodynamically by means of CALPHAD approach. Experimental results were obtained by using differential ...thermal analysis (DTA), scanning electron microscopy (SEM) with energy dispersive spectrometry (EDS), and X-ray powder diffraction (XRD) methods. Examined samples can construct two isothermal sections at 400 and 500 °C as well as three vertical sections of Cu-GeSb, Ge-CuSb, and Sb-CuGe. From equilibrated samples in Cu-rich part of the 500 °C isothermal section, one ternary compound was detected. Based on the present experimental data and available literature data, a thermodynamic description of the ternary Cu-Ge-Sb system has been developed. A reasonable agreement between experimental data and the calculated phase equilibria is obtained.
•Experimental investigation of phase equilibria at 400 °C and 500 °C.•Description of ternary τ(Cu6GeSb) compound.•Thermodynamic optimization of the ternary Cu-Ge-Sb system.•Good agreement of calculation and experimental data is reached.
Phase diagram of the ternary Al–Bi–In system was experimentally investigated using scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS) and differential thermal analysis (DTA). ...Microstructures of five alloys aged at 70 °C were determined by SEM-EDS. Phase transitions of nine alloys with compositions along three cross-sections with molar ratios Bi/In = 1, Al/Bi = 1 and Al/In = 1 were studied using DTA technique. Experimentally obtained results were compared with thermodynamically extrapolated phase diagram of the Al–Bi–In system and reasonable agreement was found.
•Phase diagram of the ternary Al–Bi–In system was investigated.•Monotectic reaction L1↔(Al)+L2 was determined by DTA results.•Ternary eutectic reaction L2↔(Al)+(Bi)+BiIn was identified.•Microstructures of aged samples were experimentally determined.•Phase equilibria were thermodynamically predicted.
Microstructure, hardness and electrical properties of the selected ternary Ag-Bi-Ge alloys were investigated in this study. Isothermal sections of the Ag-Bi-Ge system at 25, 100 and 500 °C have been ...extrapolated using optimized thermodynamic parameters from literature and experimentally investigated. Performed experiments were optical microscopy, scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS), X-ray powder diffraction (XRD), hardness measurements by Brinell method and electrical conductivity measurements. EDS results were compared with predicted phase equilibria and good overall agreement between experimental and calculated values was obtained. XRD results were also in agreement with predicted phase equilibria. Hardness and electrical conductivity of selected alloys were measured and by using appropriated mathematical model these properties were predicted in the whole composition range.
An experimental study was carried out on cold worked Cu-12.7 wt.%Au alloy and pure copper, in order to compare the properties change during thermo-mechanical treatment. Hardness, microhardness, and ...electrical conductivity were studied as a function of annealing temperature and annealing time with the purpose of investigating the intensity of anneal hardening effect in cold worked Cu-12.7 wt.%Au alloy. Isochronal (up to 350 °C) and isothermal (at 250 °C for 100 h) annealing of cold worked alloy caused a two-stage increase in all of the measured properties. The mechanism responsible for this increase was analyzed using DTA, XRD, and TEM studies. The four stages observed in DTA heating curve were discussed in connection with the occurring processes. The reduction in the lattice parameter of cold worked Cu-12.7 wt.%Au alloy during annealing at 260 °C caused by the solute clustering, was observed. TEM studies did not show any presence of precipitates, other than disk-shaped areas with a higher degree of ordering. The achievement of high mechanical properties and high electrical conductivity in cold worked Cu-12.7 wt.%Au alloy after low temperature annealing was ascribed to the comparative effects of short-range ordering and solute segregation to lattice defects.
•The anneal hardening effect appeared in cold worked Cu-12.7 wt.%Au alloy.•A significant increase in properties during the isochronal and isothermal annealing was achieved in two stages.•The mechanism for anneal hardening effect was analyzed using DTA, XRD, and TEM.•Solute segregation led to the predominant hardening mechanism although short-range ordering could not be disregarded.
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