Some Considerations Concerning the Differential Scanning Calorimetry of Ultra Tough Plastic Materials

2014 ◽  
Vol 659 ◽  
pp. 107-111
Author(s):  
Dumitru Nedelcu ◽  
Nicoleta Monica Lohan ◽  
Constantin Carausu ◽  
Octavian Pruteanu
Keyword(s):  
Differential Scanning Calorimetry ◽  
Heat Flow ◽  
Reference Value ◽  
Test Sample ◽  
Transformation Process ◽  
State Transformation ◽  
Solid State Transformation ◽  
Scanning Calorimetry ◽  
Flow Variation ◽  
Plastic Materials

The Differential Scanning Calorimetry (DSC) it’s an important analysis in research since the 20thcentury, being used is various fields such as: physics, chemistry, science and materials technology. Its applicability has also extended to other fields, such as nanothermodynamics and bio-thermodynamics. Calorimetry measures the amount of heat absorbed/dissipated by a test sample as compared to a reference value, when the test sample is subjected to a heating and/or cooling cycle. The calorimetric effect may be revealed by the temperature-and/or time-dependent heat flow variation, and its evaluation makes sense when particular heat flow variations, specific to the various transformations accompanying temperature variation, occur. The research described in this paper focuses on the study of calorimetry of ultra tough plastic materials such B4300G4 and B4300G6. The samples were obtained by injection moulding and the planning of the experiments was achieved by means of the Taguchi methodology. The differential scanning calorimetry will show the endothermal and exothermal transformations during which we measured the transformation onset and completion temperatures, as well as the temperature in the middle of the transformation process. Also will be measured the amount of absorbed and dissipated heat, respectively. The DSC diagram showed no temperature-dependent heat flow variation that could suggest a solid state transformation. This paper aims to highlight the behavior of glass transition using DSC analysis, the transformation that occurs during heating of the two polymers obtained using three injection angles: 0o, 45oand 90o.

Solid-State Reactions in Multilayer Ni/Ti Thin Film Composites

1990 ◽  
Vol 205 ◽  
Author(s):  
Gillian E. Winters ◽  
K.M. Unruh ◽  
C.P. Swann ◽  
M.E. Patt ◽  
B.E. White ◽  
...  
Keyword(s):  
Solid State ◽  
Solid State Reactions ◽  
Metastable Solid Solution ◽  
State Transformation ◽  
Solid State Transformation ◽  
Scanning Calorimetry ◽  
The Individual ◽  
Thin Film Composites ◽  
Film Composites ◽  
Rf Sputter Deposition

AbstractMultilayer films, consisting of alternating layers of crystalline Ni and Ti, have been prepared by RF sputter deposition over a range of modulation wavelengths corresponding to an overall composition of Ni50Ti50. These films have been characterized by xray diffraction and Rutherford backscattering measurements. The solid-state transformation by interdiffusional mixing of the individual layers has been directly studied by differential scanning calorimetry and correlated with structural measurements. These measurements indicate that the solid-state reaction of Ni and Ti multilayers proceeds through the formation of a metastable solid solution of Ti in Ni followed by the formation of intermetallic equilibrium compounds. No direct calorimetric or structural evidence for the formation of an amorphous Ni-Ti phase has been found in these samples.

Effects of Non-Equilibrium Solidification and Aging Treatment on Microstructure Characteristic of a Ni-Base Superalloy

2014 ◽  
Vol 664 ◽  
pp. 3-7
Author(s):  
Da Fan Li ◽  
Xiao Hu ◽  
Wei Yang
Keyword(s):  
Volume Fraction ◽  
Dendritic Structure ◽  
Aging Treatment ◽  
Interface Energy ◽  
Transformation Process ◽  
Phase Changes ◽  
State Transformation ◽  
Solid State Transformation ◽  
Coarse Dendrite ◽  
Base Superalloy

Copper mould spray casting and aging treatment were performed to investigate the microstructure evolution of a Ni-base superalloy. With increasing the cooling rate during solidification, the morphology of primary γ phase changes from coarse dendrite to fine dendritic structure with radial-like feature, accompanied by the inhibition of γ′ phase due to the shortened period during the subsequent solid state transformation process. After aging treatment, both the size and volume fraction of γ′ phase are increased with prolonging the isothermal time, which generate the morphology transition of precipitates from irregular and spherical to ellipse and rectangle due to the competition between the interface energy and strain energy.

scholarly journals Influence of Cooling Rate on Nature and Morphology of Intercellular Precipitates in Si-Mo Ductile Irons

2018 ◽  
Vol 925 ◽  
pp. 231-238
Author(s):  
Mervat Youssef ◽  
Adel Nofal ◽  
Abdelhamid Hussein
Keyword(s):  
Cooling Rate ◽  
Lamellar Structure ◽  
Wide Spectrum ◽  
State Transformation ◽  
Solid State Transformation ◽  
Scanning Calorimetry ◽  
Cooling Rates ◽  
Eutectic Carbides ◽  
Thermo Calc Software ◽  
Scanning Electron

This work is designed to better understand the influence of cooling rate on the nature and morphology of intercellular precipitates in Silicon-Molybdenum ferritic ductile iron (SiMo). Plates of 3, 6, 9 mm thickness were cast in greensand and investment casting molds to give a wide spectrum of cooling rates. It was found that at higher cooling rates, the intercellular regions have a lamellar structure typical of pearlite. With decreasing cooling rates, the precipitate contains complex (Fe-Mo-Si) carbides of fine spheroidal or rod-like structure surrounding the eutectic carbides.Intensive Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM/EDS) and Optical Microscopy (OM) investigations showed that the eutectic carbides are mainly (Fe, Mo, Si) C containing up to 48% Mo, whereas the fine precipitates contain lower Mo-contents. Both carbide types did not show to have a strict stoichometric composition. The solidification and solid-state transformation path was determined using both phase diagram calculated from Thermo-Calc software as well as Differential Scanning Calorimetry (DSC).

Electron microscopic study of the illite–smectite transformation in the bentonites from Cerro del Aguila (Toledo, Spain)

Clay Minerals ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 501-510 ◽  
Author(s):  
C. de Santiago Buey ◽  
M. Suarez Barrios ◽  
E. Garcia Romero ◽  
M. C. Dominguez Diaz ◽  
M. Doval Montoya
Keyword(s):  
Layer Structure ◽  
Interlayer Spacing ◽  
Transformation Process ◽  
Raw Material ◽  
State Transformation ◽  
Solid State Transformation ◽  
Electron Microscopic ◽  
Sem And Tem ◽  
Trioctahedral Smectite ◽  
Weathering Process

AbstractA mineralogical and microstructural study of bentonites from 'Cerro del Aguila' located in the Tagus Basin (Toledo, Spain) was carried out using XRD, SEM and TEM observations and chemical data obtained by TEM-EDX. The bentonites are mainly composed of trioctahedral smectite with a unit-cell formula (Si3.76Al0.24)(Al0.44Fe3+0.26Mg1.81)Ca0.05K0.19O10(OH)2 and small amounts of illite. The relationships between illite and smectite particles observed by SEM and TEM allowed the study of the weathering process of illite to form smectite through possible intermediate stages. The transformation begins as an exfoliation normal to the stacking direction and develops by opening of the interlayer spacing, the replacement of K+ by hydrated interlayer cations and slight reorganization of the 2:1 layer structure. The so-called solid-state transformation process then proceeds by further dissolution and the formation of a colloidal phase acting as raw material in the growth of new phyllosilicates such as smectite.

Standards, calibration, and guidelines in microcalorimetry. Part 2. Calibration standards for differential scanning calorimetry* (IUPAC Technical Report)

2006 ◽  
Vol 78 (7) ◽  
pp. 1455-1476 ◽  
Author(s):  
Giuseppe Della Gatta ◽  
Michael J. Richardson ◽  
Stefan M. Sarge ◽  
Svein Stølen
Keyword(s):  
Differential Scanning Calorimetry ◽  
Heat Capacity ◽  
Heat Flow ◽  
Flow Rate ◽  
Heat Flow Rate ◽  
Scanning Calorimetry ◽  
Calibration Standards ◽  
Technical Report ◽  
Temperature Heat ◽  
Differential Scanning Calorimeters

Differential scanning calorimeters (DSCs) are widely used for temperature, heat capacity, and enthalpy measurements in the range from subambient to high temperatures. The present recommendations describe procedures and reference materials (RMs) for the calibration of DSCs. The recommendations focus on the calibration of the response of the instrument and on the estimation of the measurement uncertainty. The procedures for temperature, enthalpy, and heat-flow rate calibration are given in detail. Calibration on cooling has also been considered. Recommended RMs are listed, and the relevant properties of these materials are discussed.

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