Article
Thermodynamics
Mikhail Yagofarov, Andrey A. Sokolov, Marat A. Ziganshin, Timur A. Mukhametzyanov, Boris N. Solomonov
Summary: Thermodynamic parameters of fusion play a crucial role in determining the solubility and stability of crystalline materials, making them important in the field of pharmaceutics. However, traditional methods such as differential scanning calorimetry face challenges due to evaporation and degradation at high temperatures. This study developed independent approaches, including solution calorimetry and fast scanning calorimetry, to accurately determine the thermodynamic parameters of melting for two active pharmaceutical ingredients. The results provide a consistent set of fusion enthalpies and heat capacities, demonstrating the viability of the solution calorimetry approach for polyfunctional organic molecules and its potential applications in studying pharmaceutically active compounds.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2023)
Article
Materials Science, Multidisciplinary
S. Terlicka, A. Debski, A. Sypien, W. Gasior, A. Budziak
Summary: This study focused on pioneering dilatometric measurements and experimental determination of the standard enthalpy of formation for alloys and intermetallic phases of the Ag-Mg system. The research included preparation, structural analysis, and dilatometric studies of alloys and intermetallic phases, showing an increase in linear coefficient of thermal expansion with the addition of Mg to Ag. The standard enthalpies of formation of the prepared alloys were consistent with literature data.
MATERIALS TODAY COMMUNICATIONS
(2021)
Article
Materials Science, Multidisciplinary
Zi Yang, Igor Erdle, Chunhui Liu, John Banhart
Summary: Differential scanning calorimetry (DSC) is a widely used technique for analyzing precipitation phenomena in alloys. However, the processes occurring during non-isothermal heating, such as cluster formation and evolution, are not well understood. In this study, we conducted experiments to measure heat, hardness, positron lifetime, electrical resistivity, and microstructure of an Al-Mg-Si alloy heated at different rates. We found that the precipitation process can be divided into stages with transition temperatures depending on the heating rate. Quenched-in excess vacancies were found to play an important role in cluster formation at lower temperatures. The results can be well simulated using a precipitation model. The methodology used in this study can be applied to investigate more complex nonisothermal heat treatments.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
J. D. Robson, A. D. Smith, J. Guo, J. M. Donoghue, A. E. Davis
Summary: Competitive continuous and discontinuous precipitation (CP and DP) in magnesium alloys have been studied in-situ for the first time. The migration of the high angle grain boundary (reaction front, RF) behind which DP occurs is found to be irregular instead of steady-state. Local effects play a key role in causing the irregular motion of the RF.
Article
Materials Science, Multidisciplinary
Robert Kahlenberg, Tomasz Wojcik, Georg Falkinger, Anna Lena Krejci, Benjamin Milkereit, Ernst Kozeschnik
Summary: By studying the evolution of metastable and Cu-containing precursor precipitates into stable beta-Mg2Si during continuous heating of an AA6061 aluminum alloy, this work reveals that the transformation mainly involves the release of atoms and rearrangement at the interfaces. Nucleation predominantly occurs at the interface between precursors and the aluminum matrix.
Article
Chemistry, Physical
A. Debski, M. Peska, J. Dworecka-Wojcik, S. Terlicka, W. Gasior, W. Gierlotka, M. Polanski
Summary: Despite years of research on the affinities of palladium and magnesium with hydrogen, information on magnesium-palladium alloys remains incomplete. While magnesium palladium alloys are unlikely to be used as solid-state hydrogen storage materials, their interaction with hydrogen may be useful for broadening knowledge or finding other applications.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Metallurgy & Metallurgical Engineering
B. Laouar, D. Hamana, A. Hayoune, Z. Belamri, L. Chetibi
Summary: The effect of plastic deformation on internal friction peaks in Al-based alloy is investigated. Cold rolling of the Al-Mg-Si alloy (AA6060) leads to the appearance of a peak P1 at medium temperature, which is attributed to the interaction between Mg or Mg-Si clouds and metastable precipitates in the strain field of dislocations. In addition, a second peak P-R at high temperature is observed in the cold rolled sample, indicating a transition from a high internal friction background to a low one due to recrystallization.
CANADIAN METALLURGICAL QUARTERLY
(2023)
Review
Metallurgy & Metallurgical Engineering
Zhang-Zhi Shi, Hong-Ting Chen, Ke Zhang, Fu-Zhi Dai, Xue-Feng Liu
Summary: Crystallography of precipitates in Mg alloys plays a crucial role in explaining and predicting alloy microstructures and properties. This study introduces a general theory of singular interface to interpret precipitate morphology and orientation relationship, summarizes recent experimental findings and theoretical advances, and proposes future research directions in this field.
JOURNAL OF MAGNESIUM AND ALLOYS
(2021)
Article
Thermodynamics
Aleksey Buzyurov, Ruslan N. Nagrimanov, Dzmitry H. Zaitsau, Timur A. Mukhametzyanov, Amir Abdelaziz, Boris N. Solomonov, Christoph Schick
Summary: In this work, a procedure for vapor pressures determination using fast scanning chip calorimeter was adapted to stagnant gas phase. The validity of this procedure was confirmed by comparing the results with literature data, showing that commercial Flash DSC devices can be used for reliable assessment of vapor pressures in a wide temperature range.
THERMOCHIMICA ACTA
(2021)
Article
Chemistry, Physical
A. Debski, W. Gasior, W. Gierlotka, M. Polanski
Summary: For the first time, the thermodynamic properties of liquid Mg-Pb-Pd alloys were studied through calorimetric measurements using a MHTC 96 drop calorimeter. Five series of liquid alloys were evaluated at a temperature of 1012 K, and the ternary excess term of the Mg-Pb-Pd liquid phase was determined based on the obtained data and the Redlich-Kister equation. Thermodynamic optimization was performed using home-made software, resulting in ternary optimized parameters. These measurements represent the initial step towards understanding the phase equilibria in the Mg-Pb-Pd system.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Article
Nanoscience & Nanotechnology
J. D. Robson, M. J. Lawson, J. M. Donoghue, J. Guo, A. E. Davis
Summary: Discontinuous precipitation (DP) is a common mechanism for solid solution decomposition, resulting in the formation of precipitate layers and solute depleted matrix along a moving boundary. The morphology of DP regions is highly complex, and the behavior of dislocations and twins within such structures during deformation is not well understood. A 3-dimensional (3D) analysis is necessary to reveal the true morphology of DP. This study presents the first 3D investigation of DP using a novel PFIB based serial sectioning method. The AZ80 alloy studied exhibits an interconnected network of DP regions within a connected matrix, with varying widths of DP regions.
SCRIPTA MATERIALIA
(2023)
Article
Chemistry, Physical
Sebastian Kulawik, Wojciech Gierlotka, Adam Debski, Wladyslaw Gasior, Andrzej Zajaczkowski
Summary: Enthalpies of mixing of liquid Ga-In-Zn alloys at 720 K were measured using high-temperature drop calorimetry, and thermodynamic optimization was carried out based on the results obtained. Phase equilibria in binary and ternary systems were then calculated and compared with results from different experimental techniques.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Nanoscience & Nanotechnology
Z. Ma, J. D. Robson
Summary: Al-Zn-Mg-Cu alloys achieve high strength mainly through precipitation strengthening. This study investigated the coupling of dislocation and precipitation strengthening in pre-aged AA7075 alloys to achieve strengths greater than those obtained with heat treatment alone. The results showed that deformation introduced sufficient dislocations for work hardening and post-ageing at 120 degrees C was effective in promoting precipitation strengthening. The time required to reach peak strength is determined by the competition between precipitation kinetics and dislocation recovery.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Materials Science, Multidisciplinary
Tomasz Trzepiecinski, Sherwan Mohammed Najm, Valentin Oleksik, Delia Vasilca, Imre Paniti, Marcin Szpunar
Summary: This article examines the opportunities and limitations of using Single- and Two Point Incremental Sheet Forming techniques for shaping aluminium and its alloys in the automotive, aviation and space industries. It summarizes research on the influence of ISF process parameters on workpiece formability and surface quality, as well as the latest trends in experimental research and finite element simulation.
Article
Nanoscience & Nanotechnology
Ruixuan Li, Zheng Ren, Yuan Wu, Zhanbing He, Peter K. Liaw, Jingli Ren, Yong Zhang
Summary: Designing a quinary alloy based on the concept of high-entropy alloys enables the achievement of high strength and deformability at high zinc content levels in Al-based alloys. The precipitation transformation plays a key role in contributing to the desired mechanical properties.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Chemistry, Physical
Luojia Zhang, Evgeny Zhuravlev, Jun Yi, Qijie Zhai, Christoph Schick, Yulai Gao, Bingge Zhao
Summary: Crystal nucleation is a crucial step in the crystallization of metallic glasses. However, the nucleation kinetics can deviate from the classical nucleation theory as the undercooling increases. This study examines the nucleation kinetics in glass and undercooled melt using nanocalorimetry. By varying the cooling rate, the processes of crystallization, homogeneous nucleation, and heterogeneous nucleation are distinguished. The critical cooling rates for suppressing crystallization and nucleation are estimated, and a well-identified amorphous phase is produced for nucleation studies. The underlying kinetic mechanism is revealed through the analysis of crystallization heat and overall heat using the Johnson-Mehl-Avrami method.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Ruslan A. Andrianov, Juern W. P. Schmelzer, Rene Androsch, Timur A. Mukhametzyanov, Christoph Schick
Summary: The specific features of crystal nucleation have a significant impact on the morphology of the crystalline material. Due to their small size and stochastic nature, it is usually difficult to observe the development of nuclei directly. However, an experimental approach using fast scanning calorimetry has been developed to determine the specific features of the cluster size distribution. This approach allows for estimating the time evolution of the largest detectable clusters in the distribution and determining their radial growth rate.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Materials Science, Ceramics
Semen E. Lapuk, Marat A. Ziganshin, Radik A. Larionov, Timur A. Mukhametzyanov, Christoph Schick, Alexander V. Gerasimov
Summary: Robust determination of parameters governing the stability of amorphous drugs is crucial in modern pharmaceutics. The kinetic stability of these systems greatly impacts their practical applications. This study determined the critical cooling rates and kinetic parameters of cold crystallization for four slowly crystallizing sulfonamides. The Nakamura crystallization model demonstrated good prognostic ability by determining the stability time profile of drug systems prone to crystallization from non-isothermal thermokinetic data.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2023)
Article
Polymer Science
Akihiko Toda, Yoshitomo Furushima, Christoph Schick
Summary: In this study, the isothermal crystallization kinetics of poly(butylene terephthalate) at low temperatures near the glass transition was investigated using chip-sensor fast scanning calorimetry. The Avrami analysis showed that the Avrami index decreased from 4 to less than 2 in the low-temperature peak of the crystallization rate, resulting in significantly low crystallinity near the glass-transition temperature. This phenomenon was attributed to the inhibition of crystal growth by the rigid amorphous fraction (RAF) that is constrained by crystals, as proposed by Schawe for other crystalline polymers. The transformation of the mobile amorphous fraction (MAF) into RAF with the progress of crystallization was confirmed near the glass-transition temperature, leading to the rigidification of all amorphous fractions.
Article
Medicine, Research & Experimental
Semen E. Lapuk, Timur A. Mukhametzyanov, Christoph Schick, Alexander Gerasimov
Summary: The application of drugs in the amorphous state is being actively researched in pharmaceutical science to enhance their bioavailability. In this study, the kinetic stability and glass-forming ability of thermally labile quinolone antibiotics were investigated using fast scanning calorimetry. The critical cooling rates for preventing crystallization of oxolinic acid, pipemidic acid, and sparfloxacin were determined to be 10,000, 40, and 80 K·s-1 respectively, indicating their strong glass-forming ability. The Nakamura model was found suitable for describing the crystallization process of the amorphous forms of the quinolone antibiotics using a combination of nonisothermal and isothermal kinetic approaches.
MOLECULAR PHARMACEUTICS
(2023)
Article
Chemistry, Multidisciplinary
Alexander Minakov, Christoph Schick
Summary: This article studies the influence of various mesoscopic effects on interfacial thermal conductance (ITC) during fast melting processes and the contributions to ITC in pre-melting and melting processes of metal microparticles. The gained knowledge is useful for understanding and optimizing technological processes involving fast melting, such as laser additive manufacturing.
APPLIED SCIENCES-BASEL
(2023)
Article
Chemistry, Multidisciplinary
Karina V. Gataullina, Aleksey V. Buzyurov, Alexander V. Gerasimov, Askar K. Gatiatulin, Marat A. Ziganshin, Christoph Schick, Valery V. Gorbatchuk
Summary: Solid-state guest exchange is an efficient method for preparing highly metastable polymorphs of indomethacin. This method allows the preparation of metastable forms with low first melting points, and the characterization of indomethacin polymorphs was performed using fast scanning calorimetry.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Physics, Multidisciplinary
Juern W. P. Schmelzer, Timur V. Tropin, Christoph Schick
Summary: In the theoretical treatment of crystallization, it is commonly assumed that liquid relaxation processes are faster than crystal nucleation and growth. However, near and below the glass transition temperature, this assumption is often not valid. Deviations from the metastable equilibrium state of the liquid must be considered when determining the kinetic coefficients, thermodynamic driving force, and surface tension of the crystal phase. These factors can greatly influence the overall crystallization process.
Article
Polymer Science
Akihiko Toda, Yoshitomo Furushima, Christoph Schick
Summary: The relationship between the changes in the crystallization kinetics and the crystal domains of poly(butylene terephthalate) was investigated under isothermal conditions. The Avrami exponent n characterizing the nucleation and growth kinetics of the crystal domains exhibited a continuous change within the target temperature range, indicating a change in the nucleation mode for spherical domains. The morphology of the crystal domains responsible for this change was identified, with a continuous change in the size of spherulites observed. The formation of 10 nm scale granular nodules with high nuclei density at low temperatures was also observed.
Article
Polymer Science
Rene Androsch, Katalee Jariyavidyanont, Andreas Janke, Christoph Schick
Summary: In this study, the melt-crystallization process of PBS under different melt-supercooling conditions was analyzed using X-ray scattering techniques, microscopy, and fast scanning chip calorimetry. It was found that lamellar thickening is not the main mechanism of isothermal secondary crystallization, and low-temperature crystallization leads to the presence of crystal defects.
Article
Chemistry, Physical
Yeong Zen Chua, Reiner Zorn, Juern W. P. Schmelzer, Christoph Schick, Olaf Holderer, Michaela Zamponi
Summary: To understand the properties of glass-forming liquids, the concept of cooperativity length is widely used. Experimental methods of determining this quantity are crucial for the understanding of both thermodynamic and kinetic properties. In this study, the cooperative length and cooperativity number were determined using AC calorimetry and QENS, and the results depended on whether temperature fluctuations were considered. The comparison between the two methods indicated that considering temperature fluctuations is important, and the cooperativity length can be derived from thermodynamic considerations.
ACS PHYSICAL CHEMISTRY AU
(2023)
Article
Chemistry, Physical
Semen Lapuk, Marina Ponomareva, Marat Ziganshin, Radik Larionov, Timur Mukhametzyanov, Christoph Schick, Ivan Lounev, Alexander Gerasimov
Summary: In this study, the glass transition of the biocompatible polymer polyvinylpyrrolidone was investigated using differential scanning calorimetry, fast scanning calorimetry, and broadband dielectric spectroscopy. The dependence of the difference in isobaric specific heat capacities between the liquid and glass on the dynamic glass transition temperature, volume, and number of particles in the cooperatively rearranging regions was determined. A linear relationship between the shift factor from the Frenkel-Kobeko-Reiner equation and the molecular mass of polyvinylpyrrolidone was established. These findings contribute to the selection of optimal excipients for the development of solid dispersions based on amorphous polymers.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Thermodynamics
Timur A. Mukhametzyanov, Ruslan A. Andrianov, Dmitrii N. Bolmatenkov, Mikhail I. Yagofarov, Boris N. Solomonov, Christoph Schick
Summary: The nucleation and crystallization of the rapidly crystallizing organic compound benzocaine show different behaviors under different supercooling conditions, and the temperature transition of nucleation and crystallization is sharp and sample-dependent.
THERMOCHIMICA ACTA
(2023)
Article
Materials Science, Multidisciplinary
Matteo Villa, Flemming B. Grumsen, Frank Niessen, Thomas Dahmen, Lingfei Cao, Michael Reich, Olaf Kessler, Xiaoxu Huang, Marcel A. J. Somers
Summary: The present investigation studied the effects of austenite aging on precipitation hardening martensitic stainless steel. It was found that austenite aging promotes the formation of copper clusters and particles, affects the kinetics and substructure of martensite formation, and significantly strengthens the material. The contribution of precipitates to the strength of martensite was interpreted using the Russell-Brown model.
Article
Polymer Science
Akihiko Toda, Yoshitomo Furushima, Christoph Schick
Summary: The relationship between changes in crystallization kinetics and crystal domains of poly(butylene terephthalate) was investigated under isothermal conditions. The study found that the nucleation and growth kinetics of the crystal domains exhibited a continuous change within a certain temperature range. This change corresponded to the nucleation mode for spherical domains, such as spherulites and nodules, which depended on whether nucleation occurred from foreign heterogeneities or from the homogeneous melt. The morphology of the crystal domains, specifically the size and formation of spherulites and granular nodules, was identified as a factor contributing to the changes in crystallization kinetics.