Structural studies of liquid Co–Sn alloys

AbstractAn analysis of the structure features of liquid Co–Sn alloys has been performed by means of X-ray diffraction method, viscosity coefficient analysis and computer simulation method. The X-ray diffraction investigations were carried out over a wide concentration range at the temperature 1473K. It was found that the structure of these alloys can be described in the frame of independent X-ray scattering model. The viscosity coefficient was calculated by an excess entropy scaling and compared with experimental data

Selective laser sintering of amorphous nanoparticles: Molecular dynamics simulations

The paper investigates the process of liquid-phase sintering of amorphous iron-based nanoparticles by the method of molecular dynamics simulations. The classical molecular dynamics package LAMMPS was used for modeling. Visual analysis of the atomic configurations of nanoparticles during their rapid cooling revealed the self-purification effect of the particles. Partial pair correlation functions and coordination number distribution functions were used to analyze the atomic structure of nanoparticles after sintering. As a result of the analysis of the main structural parameters, which were obtained using the specified functions, differences in the atomic composition and structure of the volume and surface of nanoparticles were established

Модифікація атомної структури рідкої евтектики Al0.973Ni0.027 карбоновими нанотрубками

The short-range order structure of the liquid Al0.973Ni0.027 eutectic alloy and eutectic based composites with carbon nanotubes containing 5, 10 and 15% was investigated. The changes of the main structure parameters (interatomic distances, coordination numbers, cluster sizes) was analyzed depending on the nanotubes content and temperature of the composites. As a result of the addition of carbon nanotubes, the atomic structure contracting of the liquid Al0.973Ni0.027 eutectic was revealed.Досліджено структуру ближнього порядку рідкої евтектики Al0.973Ni0.027 та композитів на її основі з вмістом карбонових нанотрубок 5, 10 та 15 об.%. Проаналізовано зміну основних структурних параметрів (міжатомних відстаней, координаційних чисел, розмірів кластера) залежно від вмісту нанотрубок та температури композитів. Виявлено що в результаті додавання карбонових нанотрубок відбувається ущільнення атомної структури рідкої евтектики Al0.973Ni0.027

Structural disordering in Sn-Pb(Bi) eutectic melts induced by heating

The structure of liquid Sn0.739Pb0.261 and Sn0.57Bi0.43 eutectic alloys was studied by means of X-ray diffraction at several temperatures. Structure factors, pair correlation functions and the main structural parameters obtained on their basis were analyzed. We show that the structure of the Sn0.739Pb0.261 and Sn0.57Bi0.43 eutectic alloys is inhomogeneous and consists of different types of clusters. Upon heating the cluster structure undergoes topological and chemical disordering showing a significant dependence of structural parameters on temperature near the melting point

Liquid-solid interaction during formation of nanocomposite systems

Structural changes in mixtures of liquid Bi with small Cu and Ni particles were studied at temperatur es of 615 and 1145K. Microstructures of the composites were observed (SEM) and analyzed after treatment at different temperatures and various durations of stirring. The structure of the mixtures of Bi with Cu(Ni) particles was investigated by means of X-ray diffraction, both in the solid and liquid state

Liquid-solid interaction during formation of nanocomposite systems

Structural changes in mixtures of liquid Bi with small Cu and Ni particles were studied at temperatur es of 615 and 1145K. Microstructures of the composites were observed (SEM) and analyzed after treatment at different temperatures and various durations of stirring. The structure of the mixtures of Bi with Cu(Ni) particles was investigated by means of X-ray diffraction, both in the solid and liquid state

The Transformation of the Structure at Heating and Mechanism of Thermal Expansion of Sn-Bi Eutectic Alloy

The short range order structures of Sn-Bi eutectic melt has been studied by means of X-ray diffraction and reverse Monte-Carlo methods within 420 – 1120 К temperature range. Temperature dependences of interatomic distances and thermal expansion coefficient within first coordination sphere were calculated. Free volume temperature variation was investigated using Voronoi-Delone statistic-geometric method. Obtained data allowed us to find the occurrence of smeared structure transformation in Sn-Bi liquid eutectic and determine the temperature range of this transformation. Results of this study have a potential application in soldering technologies, particularly at improving of interface region properties. Kew words: short range order structure, thermal expansion, free volume.</span

Correlation between diffraction and viscosity data for Bi-Ga molten alloys

This work was supported by a grant from the Fundamental Researches State Fund of Ukraine (No. F 28/329-2009).Structure of Bi(100-x)Ga(x)molten alloys containing 38 center dot 5, 50, 70 and 91 center dot 5 at. % Ga has been studied by means of X-ray diffraction method and compared with viscosity measurements data. Significant changes in the structure factor profile were observed in vicinity of the concentration 70 at. % Ga. The dynamic viscosity coefficient was calculated by use of a statistical atomic distribution model and a Born-Green kinetic theory. The concentration dependence of viscosity is in agreement with change of structure parameters obtained from diffraction data

Correlation between diffraction and viscosity data for Bi-Ga molten alloys

This work was supported by a grant from the Fundamental Researches State Fund of Ukraine (No. F 28/329-2009).Structure of Bi(100-x)Ga(x)molten alloys containing 38 center dot 5, 50, 70 and 91 center dot 5 at. % Ga has been studied by means of X-ray diffraction method and compared with viscosity measurements data. Significant changes in the structure factor profile were observed in vicinity of the concentration 70 at. % Ga. The dynamic viscosity coefficient was calculated by use of a statistical atomic distribution model and a Born-Green kinetic theory. The concentration dependence of viscosity is in agreement with change of structure parameters obtained from diffraction data