In SituObservation of Phase Transformation of Powder Sintering from Ni/TiH2Using Neutron Diffraction

2014 ◽  
pp. 967-973 ◽  
Author(s):  
Gang Chen ◽  
Klaus-Dieter Liss ◽  
Peng Cao
Keyword(s):  
Phase Transformation ◽  
Neutron Diffraction ◽  
Powder Sintering

scholarly journals Phase-transformation and precipitation kinetics in vanadium micro-alloyed steels by in-situ, simultaneous neutron diffraction and SANS

2021 ◽  
Vol 220 ◽  
pp. 117317
Author(s):  
Chrysoula Ioannidou ◽  
Alfonso Navarro-López ◽  
Robert M. Dalgliesh ◽  
Arjan Rijkenberg ◽  
Xukai Zhang ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Neutron Diffraction ◽  
Precipitation Kinetics

scholarly journals Phase Transition Kinetics in Austempered Ductile Iron (ADI) with Regard to Mo Content

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5266
Author(s):  
Martin Landesberger ◽  
Robert Koos ◽  
Michael Hofmann ◽  
Xiaohu Li ◽  
Torben Boll ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Phase Transformation ◽  
Neutron Diffraction ◽  
Ductile Iron ◽  
Retained Austenite ◽  
Length Change ◽  
Atom Probe ◽  
Carbon Accumulation ◽  
Austempered Ductile Iron ◽  
Mo Content

The phase transformation to ausferrite during austempered ductile iron (ADI) heat treatment can be significantly influenced by the alloying element Mo. Utilizing neutron diffraction, the phase transformation from austenite to ausferrite was monitored in-situ during the heat treatment. In addition to the phase volume fractions, the carbon enrichment of retained austenite was investigated. The results from neutron diffraction were compared to the macroscopic length change from dilatometer measurements. They show that the dilatometer data are only of limited use for the investigation of ausferrite formation. However, they allow deriving the time of maximum carbon accumulation in the retained austenite. In addition, the transformation of austenite during ausferritization was investigated using metallographic methods. Finally, the distribution of the alloying elements in the vicinity of the austenite/ferrite interface zone was shown by atom probe tomography (APT) measurements. C and Mn were enriched within the interface, while Si concentration was reduced. The Mo concentration in ferrite, interface and austentite stayed at the same level. The delay of austenite decay during Stage II reaction caused by Mo was studied in detail at 400 °C for the initial material as well as for 0.25 mass % and 0.50 mass % Mo additions.

On the Order-Disorder Phase Transformation of Anilinium Halides.

1981 ◽  
Vol 36 (9) ◽  
pp. 967-974 ◽  
Author(s):  
Gerhard Fecher ◽  
Alarich Weiss ◽  
Gernot Heger
Keyword(s):  
Crystal Structure ◽  
Phase Transformation ◽  
High Temperature ◽  
Low Temperature ◽  
Neutron Diffraction ◽  
Temperature Phase ◽  
Ordered Structure ◽  
Low Temperature Phase

Abstract The crystal structure of the low temperature phase of anilinium bromide, C6H5NH3⊕Br⊖, was studied by neutron diffraction at T = 100 K. The refinement supports an ordered structure. The structures of the low and high temperature phases are compared and the mechanism of the phase transformation is discussed.

scholarly journals In Situ Neutron Diffraction Study of Phase Transformation of High Mn Steel with Different Carbon Content

Crystals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 101
Author(s):  
Youngsu Kim ◽  
Wookjin Choi ◽  
Hahn Choo ◽  
Ke An ◽  
Ho-Suk Choi ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Neutron Diffraction ◽  
Strain Hardening ◽  
High Strain ◽  
Tensile Deformation ◽  
Austenite Phase ◽  
Transformation Rate ◽  
Ε Martensite ◽  
In Situ Neutron Diffraction

In situ neutron diffraction was employed to examine the phase transformation behavior of high-Mn steels with different carbon contents (0.1, 0.3, and 0.5 wt.%C). With increasing carbon contents from 0.1 C to 0.5 C, the austenite phase fraction among the constituent phases increased from ~66% to ~98%, and stacking fault energy (SFE) increased from ~0.65 to ~16.5 mJ/m2. The 0.1 C and 0.3 C steels underwent phase transformation from γ-austenite to ε-martensite or α’-martensite during tensile deformation. On the other hand, the 0.5 C steel underwent phase transformation only from γ-austenite to ε-martensite. The 0.3 C steel exhibited a low yield strength, a high strain hardening rate, and the smallest elongation. The high strain hardening of the 0.3 C alloy was due to a rapid phase transformation rate from γ-austenite to ε-martensite. The austenite of 0.5 C steel was strengthened by mechanical twinning during loading process, and the twinning-induced plasticity (TWIP) effect resulted in a large ductility. The 0.5 wt.% carbon addition stabilized the austenite phase by delaying the onset of the ε-martensite phase transformation.

scholarly journals Tracing Phase Transformation and Lattice Evolution in a TRIP Sheet Steel under High-Temperature Annealing by Real-Time In Situ Neutron Diffraction

Crystals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 360 ◽  
Author(s):  
Dunji Yu ◽  
Yan Chen ◽  
Lu Huang ◽  
Ke An
Keyword(s):  
Phase Transformation ◽  
High Temperature ◽  
Neutron Diffraction ◽  
Real Time ◽  
Retained Austenite ◽  
Sheet Steel ◽  
Carbon Diffusion ◽  
Structure Evolution ◽  
In Situ Neutron Diffraction

Real-time in situ neutron diffraction was used to characterize the crystal structure evolution in a transformation-induced plasticity (TRIP) sheet steel during annealing up to 1000 °C and then cooling to 60 °C. Based on the results of full-pattern Rietveld refinement, critical temperature regions were determined in which the transformations of retained austenite to ferrite and ferrite to high-temperature austenite during heating and the transformation of austenite to ferrite during cooling occurred, respectively. The phase-specific lattice variation with temperature was further analyzed to comprehensively understand the role of carbon diffusion in accordance with phase transformation, which also shed light on the determination of internal stress in retained austenite. These results prove the technique of real-time in situ neutron diffraction as a powerful tool for heat treatment design of novel metallic materials.

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