scholarly journals Measurement and Evaluation of Calorimetric Descriptors for the Suitability for Evolutionary High-Throughput Material Development

Metals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 149 ◽  
Author(s):  
Anastasiya Toenjes ◽  
Heike Sonnenberg ◽  
Christina Plump ◽  
Rolf Drechsler ◽  
Axel von Hehl
Keyword(s):  
Heating Rate ◽  
High Throughput ◽  
Macro Level ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Characterization Methods ◽  
Material Development ◽  
First Results ◽  
Novel Method ◽  
Measurement And Evaluation

A novel method for evolutionary material development by using high-throughput processing is established. For the purpose of this high-throughput approach, spherical micro samples are used, which have to be characterized, up-scaled to macro level and valued. For the evaluation of the microstructural state of the micro samples and the associated micro-properties, fast characterization methods based on physical testing methods such as calorimetry and universal microhardness measurements are developed. Those measurements result in so-called descriptors. The increase in throughput during calorimetric characterization using differential scanning calorimetry is achieved by accelerating the heating rate. Consequently, descriptors are basically measured in a non-equilibrium state. The maximum heating rate is limited by the possibility to infer the microstructural state from the calorimetric results. The substantial quality of the measured descriptors for micro samples has to be quantified and analyzed depending on the heating rate. In this work, the first results of the measurements of calorimetric descriptors with increased heating rates for 100Cr6 will be presented and discussed. The results of low and high heating rates will be compared and analyzed using additional microhardness measurements. Furthermore, the validation of the method regarding the suitability for the evolutionary material development includes up-scaling to macro level and therefore different sample masses will be investigated using micro and macro samples during calorimetry.

scholarly journals Analysis of Different 100Cr6 Material States Using Particle-Oriented Peening

Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1056 ◽  
Author(s):  
Anastasiya Toenjes ◽  
Nicole Wielki ◽  
Daniel Meyer ◽  
Axel von Hehl
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Plastic Deformation ◽  
Heating Rate ◽  
Differential Scanning Calorimeter ◽  
Microstructural Properties ◽  
Material Development ◽  
Heat Treated ◽  
Aisi 52100 ◽  
Novel Method

As part of a novel method for evolutionary material development, particle-oriented peening is used in this work to characterize 100Cr6 (AISI 52100) microparticles that were heat-treated by means of a differential scanning calorimeter (DSC). The plastic deformation of the samples in particle-oriented peening is correlated with the microstructural properties considering different heat-treatment variations. While the heating rate was kept constant (10 K/min) for all heat treatments, different heating temperatures (500 °C, 800 °C, 1000 °C and 1100 °C) were realized, held for 20 min and then cooled down at a rate of 50 K/min. Thereby, microstructural states with different (mechanical) properties are generated. For validation, microsections of the particles were analyzed and additional universal microhardness measurements (UMH) were performed. It could be shown that the quickly assessable plastic deformation descriptor reacts sensitively to the changes in the hardness due to the heat treatment.

Determination of Solidification Parameters Used for the Prediction of the Thixoformability of Several Steel Alloys

2006 ◽  
Vol 116-117 ◽  
pp. 54-57 ◽  
Author(s):  
Jacqueline Lecomte-Beckers ◽  
Ahmed Rassili ◽  
Marc Robelet ◽  
Claude Poncin ◽  
R. Koeune
Keyword(s):  
Differential Scanning Calorimetry ◽  
Heating Rate ◽  
Liquid Fraction ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Steel Alloys ◽  
Fraction Versus ◽  
Solidification Parameters ◽  
Industrial Heating

This paper focuses on the liquid fraction curves of several steels and the correlation between liquid fraction, temperature and heating rate. The work has been performed along two main axes. First, the solid fraction versus temperature has been obtained experimentally by differential scanning calorimetry (DSC), limited to low heating rates. Then, a shift of the liquid fraction curves has been noticed at high industrial heating rates. The quantification of this effect could not be carried out by DSC and required the elaboration of another experimental device.

Kinetics Study on Non-Isothermal Crystallization of Amorphous Alloy Mg65Cu15Ag10Y10

2011 ◽  
Vol 413 ◽  
pp. 432-438
Author(s):  
Xiao Jun Wang ◽  
Tian Dong Xia ◽  
Xue Ding Chen
Keyword(s):  
Activation Energy ◽  
Amorphous Alloy ◽  
Heating Rate ◽  
Volume Fraction ◽  
Strong Dependence ◽  
Continuous Heating ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Local Activation ◽  
Local Activation Energy

The crystallization kinetics of amorphous alloy Mg65Cu15Ag10Y10has been studied by differential scanning calorimetry in the mode of continuous heating annealing. It is found that both DSC curves and activation energy show a strong dependence on the heating rate. The activation energy for crystallization are determined as 186.1 and 184.4 KJ mol−1for the heating rates β=5-20 Kmin−1, and 107.5 and 110.0 KJmol−1for the heating rates β=20-80Kmin−1, when using the Kissinger equation and the Ozawa equation, respectively. Local activation energy at any volume fraction crystallized was obtained by the general Ozawa's isoconversional method. The average value of local activation energy for heating rates ranging from 5 to 20Kmin−1is 180.9 KJ mol−1and for heating rates ranging between 20 and 80Kmin−1is 110.2 KJ mol−1. Using the Suriñach curve fitting procedure, the kinetics mode was specified. The JMA kinetics is manifested as a rule in the early stages of the crystallization. The JMA exponent,n, initially being larger than 4 and continuously decreases to about 2 along with the development of crystallization. The NGG-like mode dominates in the advanced stages of the transformation. These two modes are mutually independent. The proportion between the JMA-like and the NGG-like modes is related to the heating rate.

Effect of Molecular Weight on Glass Transition by Differential Scanning Calorimetry

1974 ◽  
Vol 52 (18) ◽  
pp. 3170-3175 ◽  
Author(s):  
Louis-Philippe Blanchard ◽  
Jean Hesse ◽  
Shadi Lal Malhotra
Keyword(s):  
Molecular Weight ◽  
Differential Scanning Calorimetry ◽  
Heat Capacity ◽  
Glass Transition ◽  
Heating Rate ◽  
Low Molecular Weight ◽  
Glass Transitions ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Polystyrene Sample

The influence of molecular weight (900 to 1.8 × 106) on the glass transition temperature of low polydispersity polystyrene (anionically prepared) has been studied by differential scanning calorimetry at heating rates of 5 to 80 °C min−1. Over the range of molecular_weight studied, and at an extrapolated heating rate of 1 °C min−1,[Formula: see text] A thermally prepared polystyrene sample ([Formula: see text]and Pd = 3.2) showed a Tge value of 93 °C, some 10° below the value predicted by the above equation. Low molecular weight species in the highly polydisperse sample are believed to be responsible for the discrepancy. The changes in heat capacity brought about by the glass transitions are accompanied in all cases on heating by an endothermic peak and this regardless of the heating rate (even extrapolated to 1 °C min−1) or the molecular weight of the sample, suggesting that the glass transition phenomenon encountered with polystyrene is a process involving a positive heat effect.

scholarly journals Analysis of DSC (differential scanning calorimetry) thermograms of milk fat

2021 ◽  
Vol 5 (3(61)) ◽  
pp. 36-39
Author(s):  
Maltam Shamilova ◽  
Sevinj Hajiyeva
Keyword(s):  
Fatty Acids ◽  
Differential Scanning Calorimetry ◽  
Melting Point ◽  
Heat Flow ◽  
Heating Rate ◽  
Milk Fat ◽  
Oxidation Time ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Melting Properties

The object of current research is the oxidation and melting properties of milk fat samples in different heating rates. One of the most problematic issues is the evaluation dependence of temperature and oxidation time regarding to heat flow, and the estimation of attitude of enthalpy values to heating rates. In order to gain a comprehensive assessment of oxidation and melting properties of milk fat samples on differential scanning calorimeter in various heating rates, it is necessary to conduct experimental studies. The analysis was performed using the dynamic option of the differential scanning calorimetry (DSC) with the following sample heating rates: 2.5, 4, 5, 7.5, 10, 12.5, 15 °C⋅min–1. Analyses were performed on 14 samples of milk fat, thus, for each heating rate were intended to two milk fat samples. As a result of the analysis, in the proper heating rates increased, it was found, that the oxidation properties of milk fat depend on the heating rates on DSC examination. In the thermal DSC analysis, the start temperature (Ts) (inlet), the onset temperature (Ton), and the maximum heat flow-peak temperatures (Tp) of oxidation were rising gradually. All the value of oxidation increased gradually with increasing heating rate, only in the Tend values were chainable among all heating rates. However, the oxidation time of milk fat is inversely proportional to the various heating rates in DSC. The oxidation enthalpy was calculated according to the heating rates too. The masses of the samples differ from each other, albeit slightly, which the individuality in the value of enthalpy could be explained through this ratio and duration of exothermic. The melting point considers the important indicator to explain the purity of samples. Melting curves of extracted milk fat samples on DSC were characterized by endothermic behavior and observed with the mild peaks, the first and the second distinct peaks due to the low-melting triacylglycerols (with high unsaturated fatty acids content) and high-melting fats, which present in milk fat. In concluded results, the characteristics of DSC oxidation curves are melting point due to the chemical structure of the fatty acids which milk fat samples contain.

scholarly journals Melting and crystallization DSC profiles of different types of meat

2017 ◽  
Vol 23 (4) ◽  
pp. 473-481 ◽  
Author(s):  
Danica Savanovic ◽  
Radoslav Grujic ◽  
Sladjana Rakita ◽  
Aleksandra Torbica ◽  
Ranko Bozickovic
Keyword(s):  
Cooling Rate ◽  
Heating Rate ◽  
Melting Process ◽  
Longissimus Dorsi ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Beef Meat ◽  
Freezable Water ◽  
Different Types ◽  
Thermo Physical Properties

The aim of this study was to test the influence of scanning rate and meat type on the thermo-physical properties of meat and content of the freezable water in frozen meat, using differential scanning calorimetry (DSC). In this study, three types of meat were investigated: beef (M. Longissimus dorsi), pork (M. Longissimus dorsi), and chicken meat (Pectoralis major). The cooling rate affected the onset (Tcon), peak (Tc) and end (Tcend) temperatures of crystallization process of beef meat (p < 0.05). Decreasing cooling rate from 20 to 2?C/min resulted in significant (p < 0.05) change of the crystallization enthalpy (?Hc) of beef meat, from -220.17 to -168.20 J/g, respectively. Reduction of the heating rate caused significant (p < 0.05) decrease in enthalpy of melting (?Hm) for beef meat, from 228.87 to 161.13 J/g. The heating rate affected the peak (Tm) and end temperatures (Tmend) of melting process of beef meat (p < 0.05). The type of meat did not have effect on ?Hc and ?Hm as well as temperature of crystallization (Tcon, Tc and Tcend) and temperature of melting (Tm and Tmend) in meat. Significant (p < 0.05) change in freezable water content were recorded between heating rate 20 ?C/min and other heating rates, for all three meat types.

scholarly journals Melting Kinetics of Nascent Poly(tetrafluoroethylene) Powder

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 791
Author(s):  
Fotis Christakopoulos ◽  
Enrico Troisi ◽  
Theo A. Tervoort
Keyword(s):  
Kinetic Model ◽  
Heating Rate ◽  
Melting Temperature ◽  
Melting Behavior ◽  
Slow Heating ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Exponential Factor ◽  
Melting Kinetics ◽  
Kinetics Of

The melting behavior of nascent poly(tetrafluoroethylene) (PTFE) was investigated by way of differential scanning calorimetry (DSC). It is well known that the melting temperature of nascent PTFE is about 344 ∘ C, but reduces to 327 ∘ C for once molten material. In this study, the melting temperature of nascent PTFE crystals was found to strongly depend on heating rate, decreasing considerably for slow heating rates. In addition, during isothermal experiments in the temperature range of 327 ∘ C < T < 344 ∘ C, delayed melting of PTFE was observed, with complete melting only occurring after up to several hours. The melting kinetics of nascent PTFE were analyzed by means of the isoconversional methodology, and an apparent activation energy of melting, dependent on the conversion, was determined. The compensation effect was utilized in order to derive the pre-exponential factor of the kinetic model. The numerical reconstruction of the kinetic model was compared with literature models and an Avrami-Erofeev model was identified as best fit of the experimental data. The predictions of the kinetic model were in good agreement with the observed time-dependent melting of nascent PTFE during isothermal and constant heating-rate experiments.

scholarly journals Investigating the pyrolysis kinetics of Pinus sylvestris using thermogravimetric analysis

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 5577-5592
Author(s):  
Langui Xu ◽  
Jiawei Zhou ◽  
Jiong Ni ◽  
Yanru Li ◽  
Yan Long ◽  
...  
Keyword(s):  
Thermogravimetric Analysis ◽  
Pinus Sylvestris ◽  
Heating Rate ◽  
Industrial Applications ◽  
High Heating Rate ◽  
Pyrolysis Kinetics ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Model Free ◽  
Different Temperatures

Thermogravimetric analyses of Pinus sylvestris from Xinxiang were performed to investigate its kinetic characteristics, which could provide information for industrial applications. Thermal degradation experiments were conducted at various heating rates of 10 °C/min, 20 °C/min, and 60 °C/min using a thermogravimetric analysis-differential scanning calorimetry (TG-DSC) analyzer with an inert environment. The peak pyrolysis temperatures of the three major components (hemicellulose, cellulose, and lignin) were predicted by the Kissinger-Kai method, and activation energy values (Eα) were calculated. The Eα of Pinus sylvestris was also estimated by two model-free methods. The decomposition reactions of hemicellulose, cellulose, and lignin at different temperatures were the main reason for fluctuations in Eα. The time for heat transfer was less sufficient at a high heating rate compared with that at a low heating rate, which caused the temperature gradients in the samples. Therefore, the temperature of maximum exothermic peaks was higher than the maximum pyrolysis temperature. This kinetic study could be useful for providing guidance for optimizing the biomass pyrolysis process.

Reaction kinetics in the combustion synthesis of Al–Ir–Ni intermetallic compounds

2008 ◽  
Vol 23 (7) ◽  
pp. 1953-1960
Author(s):  
Kai Cai ◽  
Machiko Ode ◽  
Hideyuki Murakami
Keyword(s):  
Differential Scanning Calorimetry ◽  
Combustion Synthesis ◽  
Heating Rate ◽  
Ignition Temperature ◽  
Effective Control ◽  
Vacuum Furnace ◽  
Heating Rates ◽  
Product Density ◽  
Scanning Calorimetry ◽  
Reactant Powder

The combustion synthesis of Al50Ir48Ni2 (at.%) was conducted at different heating rates in both a differential scanning calorimetry (DSC) chamber and a vacuum furnace. It was found that a higher heating rate, a sufficient amount of reactant powder, and effective control of the heat loss facilitated the complete reaction and resulted in combusted single IrAl phase products. Otherwise, multiphase products containing IrAl, unreacted Ir, and Al3Ir were synthesized. The reactions involved in different processes were discussed in terms of the thermal competition between heat generation and loss during the reaction. All ignition temperatures were below 773 K, indicating that the combustion reaction occurs at the solid–solid state. With increasing heating rate, the ignition temperature increased while the product density decreased.

Global Kinetics of the Thermal Decomposition of Materials

1997 ◽  
Author(s):  
Azzedine Missoum ◽  
Ashwani K. Gupta ◽  
Jianrong Chen
Keyword(s):  
Heat Transfer ◽  
Activation Energy ◽  
Heating Rate ◽  
Decomposition Reaction ◽  
Decomposition Process ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Transfer Product ◽  
Product Evolution ◽  
Kinetics Of

Abstract Results on the thermal destruction behavior during the decomposition of cellulose under controlled conditions are presented. Thermogravimetric (TGA) and Differential Scanning Calorimetry (DSC) tests have been carried out on the celluose samples under conditions of various heating rate and surrounding gas environment. Pyrolysis times were also measured for different size particles having different moisture contents in a controlled mixing history reactor (CMHR). The global decomposition kinetics were investigated and it was found that the decomposition process is shifts to higher temperatures at higher heating rates as a result of the competing effects of heat and mass transfer, product diffusion and the reactions kinetics. The Arrhenius parameters for pyrolysis were determined using a first order decomposition reaction of the type, dm = −km dt. It was found that the activation energy, heat of pyrolysis and char yield are a strong function of the heating rate. An increase in heating rate from 5 to 60°C/min resulted in a change of activation energy from 204.19 to 138.31 kJ/mole °C. This heating rate dependence of the kinetics is discussed. The overall decomposition process of the examined materials is generally endothermic. In general, heat transfer, mass diffusion, product evolution, heating rate, temperature and environment are the parameters that control the decomposition process. It was also shown that heat transfer and mass transport have the most effects on the decomposition process.

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