Characterization of Alloys and Liquidus Projections of Ternary Bi-Sb-Sn system

2012 ◽  
Vol 31 (1) ◽  
Author(s):  
Duško Minić ◽  
Milan Kolarević ◽  
Dragan Manasijević ◽  
Vladan Ćosović ◽  
Dragana Živković ◽  
...  

AbstractGiven that Sn-based lead-free solders are considered as possible substitution for standard lead-tin solders, properties of the alloys from ternary Bi-Sb-Sn system were characterized by microstructural SEM-EDS analysis, Brinell hardness tests, and electrical conductivity measurements. Isothermal cross section at 298 K and liquidus surface projection were calculated by application of CALPHAD method and software package PANDAT 8.1. The experimentally determined phase compositions in analyzed microstructures were found to be in a good agreement with phases on calculated cross sections.

2008 ◽  
Vol 62 (3) ◽  
pp. 148-152
Author(s):  
Aleksandra Milosavljevic ◽  
Dragana Zivkovic ◽  
Dragan Manasijevic ◽  
Nadezda Talijan ◽  
Aleksandar Grujic ◽  
...  

Lead-free soldering has become very popular in the world recently, especially in electronics, because of high ecological demands in industry. Some of lead-free solder alloys are already used in electronic industry, but despite that investigations are still going in order to find suitable replacement for Pb-Sn standard solder. In this paper phase equilibria and characterization of Sn-In-Ag alloys in section In:Ag = 7:3 are investigated. The results of phase diagram calculation are obtained by ThermoCalc software, and characteristic temperatures by DSC method. The results of XRD analysis, optical microscopy, microhardness and electrical conductivity are also presented. These results are given in order to contribute the knowledge about lead-free solders, especially Sn-In-Ag solder alloys, which are potential candidates for replacement standard lead solders.


2020 ◽  
Vol 42 (1) ◽  
pp. 70-70
Author(s):  
Ismail Topcu Ismail Topcu ◽  
Burcu Nilg n etiner Burcu Nilg n etiner ◽  
Arif N G ll o lu and zkan G lsoy Arif N G ll o lu and zkan G lsoy

This study investigates the effects of addition of Carbon nanotube (CNT) at different volume ratios (0.5- 5%) into Ti6Al4V matrix by mechanical alloying in terms of the density, microstructure, hardness and creep under dynamic load. As a result of the good bonding of carbon nanotubes powders with the main matrix, Ti-6Al-4V/CNT composites have experienced change both in microstructure and mechanical properties (such as hardness, density) and, correspondingly, qualitatively creep behaviour of Ti-6Al - 4V matrix alloy has been improved compared to the lean one. The density of CNT reinforced Ti6Al4V composites sintered at 1300and#176;C for 3h decreases with increasing CNT content. The hardness tests indicated that the hardness of composites increased with CNT addition. In addition, although creep strain is decreased continually with CNT content until 5%, creep life increased with increasing CNT content until 4% of CNT but decreased above 4%. After sintering at 1300 and#176;C under vacuum for 3 hours the density of the composite material reached to a level of 98.5 %, the microhardness to 538 HV and the creep behaviour was improved. The characterization of Ti6Al4V / CNT composites after mechanical alloying was carried out using scanning electron microscopy (SEM), energy dispersive x-rays spectroscopy (EDS) analysis and X-ray diffraction (XRD) methods. Although Ti–6Al–4V alloys are used as biomaterial, this study aimed at using MWCNTs containing Ti-6Al-4V composites at high temperature applications. Because MWCNTs reinforced Ti-6Al-4V composites are cheaper and have lower weight than the other materials used in this kind of applications.


2021 ◽  
Vol 43 ◽  
pp. 93-99
Author(s):  
Cledson dos Santos Magalhães ◽  
Rafaela Damasceno Sá ◽  
Solma Lúcia Souto Maior de Araújo Baltar ◽  
Karina Perrelli Randau

Para enriquecer el enriquecer el conocimiento sobre Trema micrantha (L.) Blume, esta investigación tuvo como objetivo realizar la caracterización anatómica, histoquímica y fitoquímica de las hojas de la especie. Se realizaron cortes transversales del pecíolo y limbo, así como cortes paradérmicos del limbo, analizados en microscopía óptica y polarizada. Se utilizaron diferentes reactivos para el análisis histoquímico. Se han descrito estructuras anatómicas que proporcionan un diagnóstico detallado de las especies estudiadas. La histoquímica mostró la presencia de metabolitos esenciales (flavonoides, taninos, entre otros) para la especie y mediante análisis SEM-EDS se confirmó que los cristales están compuestos por oxalato de calcio. El análisis fitoquímico permitió la identificación de mono y sesquiterpenos, triterpenos y esteroides, entre otros. El estudio proporcionó datos sin precedentes sobre la especie, ampliando la información científica de T. micrantha. In order to enrich the knowledge about Trema micrantha (L.) Blume, this research aims to perform the anatomical, histochemical and phytochemical characterization of the leaves of this species. Cross sections of the petiole and limbus were made, as well as paradermic sections of the limbus, analyzed in optical and polarized microscopy. Different reagents were used for histochemical analysis. Anatomical structures have been described and provide a detailed diagnosis of the species studied. Histochemistry showed the presence of essential metabolites (flavonoids, tannins, among others) for the species and through SEM-EDS analysis it was confirmed that the crystals are composed of calcium oxalate. Phytochemical analysis allowed the identification of mono and sesquiterpenes, triterpenes and steroids, among others. The study provided unprecedented data on the species, expanding the scientific information of T. micrantha.


Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1259
Author(s):  
Dmitry Kozlov ◽  
Irina Munina ◽  
Pavel Turalchuk ◽  
Vitalii Kirillov ◽  
Alexey Shitvov ◽  
...  

A new implementation of a beam-steering transmitarray is proposed based on the tiled array architecture. Each pixel of the transmitarray is manufactured as a standalone unit which can be hard-wired for specific transmission characteristics. A set of complementary units, providing reciprocal phase-shifts, can be assembled in a prescribed spatial phase-modulation pattern to perform beam steering and beam forming in a broad spatial range. A compact circuit model of the tiled unit cell is proposed and characterized with full-wave electromagnetic simulations. Waveguide measurements of a prototype unit cell have been carried out. A design example of a tiled 10 × 10-element 1-bit beam-steering transmitarray is presented and its performance benchmarked against the conventional single-panel, i.e., unibody, counterpart. Prototypes of the tiled and single-panel C-band transmitarrays have been fabricated and tested, demonstrating their close performance, good agreement with simulations and a weak effect of fabrication tolerances. The proposed transmitarray antenna configuration has great potential for fifth-generation (5G) communication systems.


Author(s):  
Charles J. Oswald

Measurements made on a long span reinforced concrete arch culvert under 7.3 m (24 ft) of silty clay backfill were compared with results from finite-element analyses of the soil-structure system using the CANDE finite-element code. The culvert strains and deflections and the soil pressure on the culvert were measured during construction and during the following 2.5 years at three instrumented cross sections. The CANDE program was modified to account for the effects of concrete creep and shrinkage strains after it was noted that the measured postconstruction culvert deflection and strains increased significantly whereas the measured soil pressure on the culvert remained relatively constant. Good agreement was generally obtained between measured and calculated values of the culvert strain and deflection and the soil pressure during the entire monitoring period after the code was modified.


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1223
Author(s):  
Elisa Ficarella ◽  
Mohammad Minooei ◽  
Lorenzo Santoro ◽  
Elisabetta Toma ◽  
Bartolomeo Trentadue ◽  
...  

This article presents a very detailed study on the mechanical characterization of a highly nonlinear material, the immature equine zona pellucida (ZP) membrane. The ZP is modeled as a visco-hyperelastic soft matter. The Arruda–Boyce constitutive equation and the two-term Prony series are identified as the most suitable models for describing the hyperelastic and viscous components, respectively, of the ZP’s mechanical response. Material properties are identified via inverse analysis based on nonlinear optimization which fits nanoindentation curves recorded at different rates. The suitability of the proposed approach is fully demonstrated by the very good agreement between AFM data and numerically reconstructed force–indentation curves. A critical comparison of mechanical behavior of two immature ZP membranes (i.e., equine and porcine ZPs) is also carried out considering the information on the structure of these materials available from electron microscopy investigations documented in the literature.


1976 ◽  
Vol 54 (7) ◽  
pp. 748-752 ◽  
Author(s):  
B. Niewitecka ◽  
L. Krause

The disorientation of 62P1/2 cesium atoms, induced in collisions with noble gas atoms in their ground states, was systematically investigated by monitoring the depolarization of cesium resonance fluorescence in relation to noble gas pressures. The Cs atoms, contained together with a buffer gas in a fluorescence cell and located in zero magnetic field, were excited and oriented by irradiation with circularly polarized 8943 Å resonance radiation, and the resonance fluorescence, emitted in an approximately backward direction, was analyzed with respect to circular polarization. The experiments yielded the following disorientation cross sections which have been corrected for the effects of nuclear spin: Cs–He: 4.9 ± 0.7 Å2; Cs–Ne: 2.1 ± 0.3 Å2; Cs–Ar: 5.6 ± 0.8 Å2; Cs–Kr: 5.8 ± 0.9 Å2; Cs–Xe: 6.3 ± 0.9 Å2. The results are in good agreement with most of the available zero-field and low-field data.


2011 ◽  
Vol 24 (6) ◽  
pp. 777-788 ◽  
Author(s):  
J.Z. Liang

The structure of the interlayer between matrix and inclusions affect directly the mechanical and physical properties of inorganic particulate-filled polymer composites. The interlayer thickness is an important parameter for characterization of the interfacial structure. The effects of the interlayer between the filler particles and matrix on the mechanical properties of polymer composites were analyzed in this article. On the basis of a simplified model of interlayer, an expression for estimating the interlayer thickness ([Formula: see text]) was proposed. In addition, the relationship between the [Formula: see text] and the particle size and its concentration was discussed. The results showed that the calculations of the [Formula: see text] and thickness/particle diameter ratio ([Formula: see text]) increased nonlinearly with an increase of the volume fraction of the inclusions. Moreover, the predictions of [Formula: see text] and the relevant data reported in literature were compared, and good agreement was found between them.


2017 ◽  
Vol 146 ◽  
pp. 03026 ◽  
Author(s):  
Diego Tarrío ◽  
Alexander V. Prokofiev ◽  
Cecilia Gustavsson ◽  
Kaj Jansson ◽  
Erik Andersson-Sundén ◽  
...  

2016 ◽  
Author(s):  
Anna Totterdill ◽  
Tamás Kovács ◽  
Wuhu Feng ◽  
Sandip Dhomse ◽  
Christopher J. Smith ◽  
...  

Abstract. Fluorinated compounds such as NF3 and C2F5Cl (CFC-115) are characterised by very large global warming potentials (GWPs) which result from extremely long atmospheric lifetimes and strong infrared absorptions in the atmospheric window. In this study we have experimentally determined the infrared absorption cross-sections of NF3 and CFC-115, calculated the radiative forcing and efficiency using two radiative transfer models and identified the effect of clouds and stratospheric adjustment. The infrared cross sections are in good agreement with previous measurements, whereas the resulting radiative forcings and efficiencies are, on average, around 10 % larger. A whole atmosphere chemistry-climate model was used to determine the atmospheric lifetimes of NF3 and CFC-115 to be (616 ± 34) years and (492 ± 22) years, respectively. The GWPs for NF3 are estimated to be 14 600, 19 400 and 21 400 over 20, 100 and 500 years, respectively. Similarly, the GWPs for CFC-115 are 6120, 8060 and 8630 over 20, 100 and 500 years, respectively.


Sign in / Sign up

Export Citation Format

Share Document