A Differential Scanning Calorimetric Study of Carbide Transition in 10Cr Tempered Martensitic Steels

2015 ◽  
Vol 1754 ◽  
pp. 37-42
Author(s):  
H.C. Wang
Keyword(s):  
Electron Microscopy ◽  
Carbide Precipitation ◽  
The Other ◽  
Differential Scanning Calorimetric ◽  
Calorimetric Study ◽  
Martensitic Steels ◽  
Scanning Calorimetry ◽  
Precise Understanding ◽  
Kinetics Of

ABSTRACTThe process and kinetics of carbide precipitation upon tempering of an Fe-10Cr-0.15C (wt.%) alloy fabricated from high-purity components has been studied. Differential scanning calorimetry reveals three exotherms in a temperature range of 100-700°C. Using advanced electron microscopy and Kissinger analysis, the exothermic processes have been interpreted. Cementite precipitated first upon tempering at temperatures as low as 200°C; M7C3 and M23C6 appear at higher temperatures, precipitating at approximately the same time but on different sites (M7C3 within grains and laths and M23C6 on grain and lath boundaries). Subsequently, the more stable M23C6 coarsens at the expense of M7C3, which dissolves. The first exotherm was interpreted as being related to the precipitation of cementite whilst the other two overlapping exotherms were interpreted as relating to the concurrent precipitation and coarsening of M7C3 and M23C6, respectively. In-situ SEM and TEM observation is being conducted in order to obtain a more precise understanding and further validate the interpretation of the DSC results.

Sporogenesis and septum schizolysis in Dipodascus aggregates

1989 ◽  
Vol 67 (7) ◽  
pp. 2150-2153 ◽  
Author(s):  
A. Tsuneda ◽  
S. Murakami
Keyword(s):  
Electron Microscopy ◽  
Freeze Drying ◽  
The Other ◽  
Cross Wall

Asci, ascospores, and arthroconidia of Dipodascus aggregatus were examined by electron microscopy. Freeze-drying of mature asci caused rupture of the ascal walls and made it possible to observe capsulated ascospores in situ. Two types of septa occurred: (i) one having a remarkably thickened cross wall which protruded to form a circumferential ridge on the hyphae, and (ii) the other without such a bulging ridge. Schizolysis of these septa resulted in the formation of morphologically distinct arthroconidia. The scizolytic process of the ridged septa was demonstrated in detail. There was no evidence to support that the plasmadesmal canals in the septa function as disjunctive pegs in the process of arthroconidial separation.

Growth kinetics of CoSi2 and Ge islands observed with in situ transmission electron microscopy

Micron ◽  
1999 ◽  
Vol 30 (1) ◽  
pp. 21-32 ◽  
Author(s):  
F.M. Ross ◽  
P.A. Bennett ◽  
R.M. Tromp ◽  
J. Tersoff ◽  
M. Reuter
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Growth Kinetics ◽  
Transmission Electron ◽  
Kinetics Of

In-Situ Transmission Electron Microscopy and Computer Simulation Study of the Kinetics of Oxygen Loss in Yba2Cu3OZ

1989 ◽  
Vol 169 ◽  
Author(s):  
C. P. Burmester ◽  
L. T. Wille ◽  
R. Gronsky ◽  
B. T. Ahn ◽  
V. Y. Lee ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Computer Simulation Study ◽  
Oxygen Loss ◽  
Domain Structures ◽  
Transmission Electron ◽  
Kinetics Of ◽  
Image Simulations

AbstractHigh resolution transmission electron microscopy during in‐situ quenching of YBa2Cu3Oz is used to study the kinetics of microdomain formation during oxygen loss in this system. Image simulations based on atomic models of oxygen‐vacancy order in the basal plane of this material generated by Monte Carlo calculations are used to interpret high resolution micrographs of the structures obtained by quenching. The observed domain structures agree well with those obtained from the simualtions.

Reactions in Metal-Metalloid Multilayers

1993 ◽  
Vol 311 ◽  
Author(s):  
Robert Sinclair ◽  
Toyohiko J. Konno
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Reactive Systems ◽  
Nucleation And Growth ◽  
In Situ Observation ◽  
Scanning Calorimetry ◽  
Compound Formation ◽  
Transmission Electron

ABSTRACTWe have studied the reactions at metal-metalloid interfaces using high resolution transmission electron microscopy, including in situ observation, and differential scanning calorimetry. There is contrasting behavior depending on the affinity for interaction or segregation. For reactive systems, compound formation ultimately results, but this can be preceded by solidstate amorphization. For non-reactive systems, crystallization of the metalloid is often achieved with nucleation and growth mediated by the metal phase.

Preparation, characterization, and properties of polystyrene/Na-montmorillonite composites

2018 ◽  
Vol 32 (8) ◽  
pp. 1078-1091 ◽  
Author(s):  
Sibel Erol Dağ ◽  
Pınar Acar Bozkurt ◽  
Fatma Eroğlu ◽  
Meltem Çelik
Keyword(s):  
Electron Microscopy ◽  
Interlayer Spacing ◽  
Decomposition Temperature ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Sem Images ◽  
Specific Pore Volume ◽  
Transmission Electron ◽  
Thermal Stability Of

A series of polystyrene (PS)/unmodified Na-montmorillonite (Na-MMT) composites were prepared via in situ radical polymerization. The prepared composites were characterized using various techniques. The presence of various functional groups in the unmodified Na-MMT and PS/unmodified Na-MMT composite was confirmed by Fourier transform infrared spectroscopy. Morphology and particle size of prepared composites was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). According to the XRD and TEM results, the interlayer spacing of MMT layers was expanded. SEM images showed a spongy and porous-shaped morphology of composites. TEM revealed the Na-MMT intercalated in PS matrix. The thermal stability of PS/unmodified Na-MMT composites was significantly improved as compared to PS, which is confirmed using thermogravimetric analysis (TGA). The TGA curves indicated that the decomposition temperature of composites is higher at 24–51°C depending on the composition of the mixture than that of pure PS. The differential scanning calorimetry (DSC) results showed that the glass transition temperature of composites was higher as compared to PS. The moisture retention, water uptake, Brunauer–Emmett–Teller specific surface area, and specific pore volume of composites were also investigated. Water resistance of the composites can be greatly improved.

Evaluation of intercalation and interaction in in-situ polymerized PLA-HNT bionanocomposites

2020 ◽  
pp. 096739112092779
Author(s):  
P Manju ◽  
P Santhana Gopala Krishnan ◽  
SK Nayak
Keyword(s):  
Electron Microscopy ◽  
Halloysite Nanotubes ◽  
Poly Lactic Acid ◽  
Resonance Spectroscopy ◽  
Hydroxyl Groups ◽  
Scanning Calorimetry ◽  
Transmission Electron Microscopy Analysis ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis

We report the in-situ synthesis of poly(lactic acid)–halloysite nanotubes (PLA-HNT) bionanocomposites, with a perspective to improve the interaction between PLA and HNT. Three PLA-HNT bionanocomposites with different HNT weight percentages were synthesized by polycondensation, followed by azeotropic distillation technique. Fourier transform infrared spectroscopy studies indicated the existence of hydrogen bonding between terminal hydroxyl groups of PLA and Si–O–Si groups present in the outer surface of HNT. Wide-angle X-ray diffraction, 29Si- and 27Al-nuclear magnetic resonance spectroscopy analysis confirmed the intercalation of PLA into HNT. Scanning electron microscopy analysis confirmed that there was no significant agglomeration and PLA matrix was found to be embedded with HNT. Transmission electron microscopy analysis also gave ample proof to substantiate the intercalation of PLA chains into HNT. Studies on zeta potential of PLA-HNT bionanocomposites, as compared with PLA, also confirmed the interactions between PLA and HNT. Single melting peak in differential scanning calorimetry analysis indicated the existence of one form of crystalline structure.

A Model for Formation and Consumption of Transient Phase

2011 ◽  
Vol 172-174 ◽  
pp. 646-651 ◽  
Author(s):  
Gamra Tellouche ◽  
Khalid Hoummada ◽  
Dominique Mangelinck ◽  
Ivan Blum
Keyword(s):  
Differential Scanning Calorimetry ◽  
Phase Formation ◽  
Transient Phase ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Proposed Model ◽  
Transient Phases ◽  
Kinetics Of

The phase formation sequence of Ni silicide for different thicknesses is studied by in situ X ray diffraction and differential scanning calorimetry measurements. The formation of a transient phase is observed during the formation of δ-Ni2Si; transient phases grow and disappear during the growth of another phase. A possible mechanism is proposed for the transient phase formation and consumption. It is applied to the growth and consumption of θ-Ni2Si. A good accordance is found between the proposed model and in situ measurement of the kinetics of phase formation obtained by x-ray diffraction and differential scanning calorimetry for higher thickness.

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