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Niculescu F, Pencea I, Iacob G, Ghiţă M, Stănescu MM, Petrescu MI, Niculescu EL, Buţu M, Stăncel CD, Şerban N, Şolea RM, Ilie AA. Thermodynamic Assessment of Molten Bi x-Sn 1-x (x = 0.1 to 0.9) Alloys and Microstructural Characterization of Some Bi-Sn Solder Alloys. MATERIALS (BASEL, SWITZERLAND) 2024; 17:1579. [PMID: 38612093 PMCID: PMC11012656 DOI: 10.3390/ma17071579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 03/26/2024] [Accepted: 03/27/2024] [Indexed: 04/14/2024]
Abstract
Properties such as lower melting temperature, good tensile strength, good reliability, and well creep resistance, together with low production cost, make the system Bi-Sn an ideal candidate for fine soldering in applications such as reballing or reflow. The first objective of the work was to determine the thermodynamic quantities of Bi and Sn using the electromotive force measurement method in an electrolytic cell (Gibbs' enthalpies of the mixture, integral molar entropies, and the integral molar excess entropies were determined) at temperatures of 600 K and 903 K. The second objective addressed is the comprehensive characterization of three alloy compositions that were selected and elaborated, namely Bi25Sn75, Bi50Sn50, and Bi75Sn25, and morphological and structural investigations were carried out on them. Optical microscopy and SEM-EDS characterization revealed significant changes in the structure of the elaborated alloys, with all phases being uniformly distributed in the Bi50Sn50 and Bi75Sn25 alloys. These observations were confirmed by XRD and EDP-XRFS analyses. Diffractometric analysis reveals the prevalence of metallic Bi and traces of Sn, the formation of the Sn0.3Bi0.7, Sn0.95Bi0.05 compounds, and SnO and SnO2 phases.
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Affiliation(s)
- Florentina Niculescu
- Faculty of Materials Science and Engineering, National University of Science and Technology Politehnica Bucharest, 313 Splaiul Independentei, J Building, 060042 Bucharest, Romania; (F.N.); (I.P.); (M.-I.P.); (E.-L.N.); (M.B.); (C.-D.S.); (N.Ş.); (R.-M.Ş.); (A.-A.I.)
| | - Ion Pencea
- Faculty of Materials Science and Engineering, National University of Science and Technology Politehnica Bucharest, 313 Splaiul Independentei, J Building, 060042 Bucharest, Romania; (F.N.); (I.P.); (M.-I.P.); (E.-L.N.); (M.B.); (C.-D.S.); (N.Ş.); (R.-M.Ş.); (A.-A.I.)
| | - Gheorghe Iacob
- Faculty of Materials Science and Engineering, National University of Science and Technology Politehnica Bucharest, 313 Splaiul Independentei, J Building, 060042 Bucharest, Romania; (F.N.); (I.P.); (M.-I.P.); (E.-L.N.); (M.B.); (C.-D.S.); (N.Ş.); (R.-M.Ş.); (A.-A.I.)
| | - Mihai Ghiţă
- National R&D Institute for Non-Ferrous and Rare Metals—IMNR, 102 Biruintei, 077145 Pantelimon, Romania
| | - Mariana-Mirela Stănescu
- Faculty of Applied Sciences, National University of Science and Technology Politehnica Bucharest, 313 Splaiul Independentei, J Building, 060042 Bucharest, Romania;
| | - Mircea-Ionuţ Petrescu
- Faculty of Materials Science and Engineering, National University of Science and Technology Politehnica Bucharest, 313 Splaiul Independentei, J Building, 060042 Bucharest, Romania; (F.N.); (I.P.); (M.-I.P.); (E.-L.N.); (M.B.); (C.-D.S.); (N.Ş.); (R.-M.Ş.); (A.-A.I.)
| | - Emanuel-Laurenţiu Niculescu
- Faculty of Materials Science and Engineering, National University of Science and Technology Politehnica Bucharest, 313 Splaiul Independentei, J Building, 060042 Bucharest, Romania; (F.N.); (I.P.); (M.-I.P.); (E.-L.N.); (M.B.); (C.-D.S.); (N.Ş.); (R.-M.Ş.); (A.-A.I.)
| | - Mihai Buţu
- Faculty of Materials Science and Engineering, National University of Science and Technology Politehnica Bucharest, 313 Splaiul Independentei, J Building, 060042 Bucharest, Romania; (F.N.); (I.P.); (M.-I.P.); (E.-L.N.); (M.B.); (C.-D.S.); (N.Ş.); (R.-M.Ş.); (A.-A.I.)
| | - Constantin-Domenic Stăncel
- Faculty of Materials Science and Engineering, National University of Science and Technology Politehnica Bucharest, 313 Splaiul Independentei, J Building, 060042 Bucharest, Romania; (F.N.); (I.P.); (M.-I.P.); (E.-L.N.); (M.B.); (C.-D.S.); (N.Ş.); (R.-M.Ş.); (A.-A.I.)
| | - Nicolae Şerban
- Faculty of Materials Science and Engineering, National University of Science and Technology Politehnica Bucharest, 313 Splaiul Independentei, J Building, 060042 Bucharest, Romania; (F.N.); (I.P.); (M.-I.P.); (E.-L.N.); (M.B.); (C.-D.S.); (N.Ş.); (R.-M.Ş.); (A.-A.I.)
| | - Roxana-Marina Şolea
- Faculty of Materials Science and Engineering, National University of Science and Technology Politehnica Bucharest, 313 Splaiul Independentei, J Building, 060042 Bucharest, Romania; (F.N.); (I.P.); (M.-I.P.); (E.-L.N.); (M.B.); (C.-D.S.); (N.Ş.); (R.-M.Ş.); (A.-A.I.)
| | - Andrei-Alexandru Ilie
- Faculty of Materials Science and Engineering, National University of Science and Technology Politehnica Bucharest, 313 Splaiul Independentei, J Building, 060042 Bucharest, Romania; (F.N.); (I.P.); (M.-I.P.); (E.-L.N.); (M.B.); (C.-D.S.); (N.Ş.); (R.-M.Ş.); (A.-A.I.)
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Theoretical Study on Thermal Stresses of Metal Bars with Different Moduli in Tension and Compression. METALS 2022. [DOI: 10.3390/met12020347] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Extensive studies have shown that engineering materials, including metals and their oxides, will present different mechanical properties in tension or compression; however, this difference is generally neglected due to the complexity of the analysis. In this study, we theoretically analyze the thermal stress of a metal bar with a bimodular effect. First, the common strain suppression method is used to obtain a one-dimensional thermal stress expression. As a contrast with the one-dimensional solution, a two-dimensional thermoelasticity solution is also derived, based on the classical Duhamel theorem concerning body force analogy. Results indicate an important phenomenon that the linear temperature rise mode will produce thermal stress in a bimodular metal bar, whereas there is no thermal stress in the case of singular modulus. If the equilibrium relation is needed to be satisfied, the variation trend between different moduli and different thermal expansion coefficients in tension and compression should be opposite. In addition, the amplitude of stress variation, from the maximum tensile stress to the maximum compressive stress, increases dramatically. There exists an inevitable link between one- and two-dimensional solutions. These results are helpful to the refined analysis and measurements of the thermophysical properties of metals and their oxides.
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Special Issue: Thermal Analysis of Materials. MATERIALS 2021; 14:ma14174923. [PMID: 34501013 PMCID: PMC8433685 DOI: 10.3390/ma14174923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 08/27/2021] [Indexed: 11/17/2022]
Abstract
The measurement of any physical property as a function of temperature brings the method used into the realm of thermal analysis [...].
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Kim HG, Lee J, Makov G. Phase Diagram of Binary Alloy Nanoparticles under High Pressure. MATERIALS 2021; 14:ma14112929. [PMID: 34072298 PMCID: PMC8199147 DOI: 10.3390/ma14112929] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 05/23/2021] [Accepted: 05/24/2021] [Indexed: 11/16/2022]
Abstract
CALPHAD (CALculation of PHAse Diagram) is a useful tool to construct phase diagrams of various materials under different thermodynamic conditions. Researchers have extended the use of the CALPHAD method to nanophase diagrams and pressure phase diagrams. In this study, the phase diagram of an arbitrary A–B nanoparticle system under pressure was investigated. The effects of the interaction parameter and excess volume were investigated with increasing pressure. The eutectic temperature was found to decrease in most cases, except when the interaction parameter in the liquid was zero and that in the solid was positive, while the excess volume parameter of the liquid was positive. Under these conditions, the eutectic temperature increased with increasing pressure.
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Affiliation(s)
- Han Gyeol Kim
- Department of Materials Science and Engineering, Korea University, Seoul 02841, Korea;
| | - Joonho Lee
- Department of Materials Science and Engineering, Korea University, Seoul 02841, Korea;
- Correspondence: (J.L.); (G.M.)
| | - Guy Makov
- Department of Materials Engineering, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
- Correspondence: (J.L.); (G.M.)
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