scholarly journals Work Hardening, Dislocation Structure, and Load Partitioning in Lath Martensite Determined by In Situ Neutron Diffraction Line Profile Analysis

2017 ◽  
Vol 48 (9) ◽  
pp. 4080-4092 ◽  
Author(s):  
Stefanus Harjo ◽  
Takuro Kawasaki ◽  
Yo Tomota ◽  
Wu Gong ◽  
Kazuya Aizawa ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Line Profile ◽  
Dislocation Structure ◽  
Work Hardening ◽  
Profile Analysis ◽  
Lath Martensite ◽  
Line Profile Analysis ◽  
Diffraction Line Profile ◽  
In Situ Neutron Diffraction

Quantitative characterization of the microstructure of heat-treated Zr-Excel by neutron line profile analysis

2016 ◽  
Vol 49 (5) ◽  
pp. 1609-1623 ◽  
Author(s):  
Kazi F. Ahmmed ◽  
Levente Balogh ◽  
Yasir Idrees ◽  
Hongbing Yu ◽  
Fei Long ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Neutron Diffraction ◽  
Line Profile ◽  
Dislocation Structure ◽  
Profile Analysis ◽  
Industrial Applications ◽  
Line Profile Analysis ◽  
Bimodal Microstructure ◽  
Solution Treated ◽  
Heat Treated

Neutron diffraction line profile analysis (DLPA) and transmission electron microscopy were used to characterize the components of the bimodal microstructure of Zr-Excel (Zr–3.5Sn–0.8Mo–0.8Nb), a nuclear structural material. The dual microstructure, consisting of equiaxed primary grains and martensitic domains both having hexagonal close-packed (h.c.p.) α crystal structure, forms when the as-received Zr-Excel alloy is heat treated at a high temperature and subsequently quenched, i.e. is solution treated. Because both microstructure components have the same crystal structure the reflections from the two components overlap significantly. The article presents how the multi-phase analysis capability of modern DLPA methods can be used to model the measured neutron diffraction patterns as the sum of two sub-patterns corresponding to the components of such a bimodal microstructure, which can be found in many hexagonal alloys relevant for industrial applications. The results show that the large equiaxed primary h.c.p. α grains have a highly correlated low-density dislocation structure and large sub-grains (∼300 nm), while the large martensitic domains have a randomly arranged very high density dislocation structure and sub-grains the size of ∼30 nm. The significantly different defect structures of the primary and martensitic phases manifest as large differences in the hardness and ductility of the individual components. As a result of this duality of the mechanical properties, solution-treated Zr-Excel materials can be considered as analogous to metal matrix composites where a softer ductile matrix contains a harder brittle reinforcing phase.

Study of tempering behavior of lath martensite using in situ neutron diffraction

2015 ◽  
Vol 107 ◽  
pp. 29-32 ◽  
Author(s):  
Z.M. Shi ◽  
W. Gong ◽  
Y. Tomota ◽  
S. Harjo ◽  
J. Li ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Lath Martensite ◽  
In Situ Neutron Diffraction

scholarly journals Correlating work hardening with co-activation of stacking fault strengthening and transformation in a high entropy alloy using in-situ neutron diffraction

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
M. Frank ◽  
S. S. Nene ◽  
Y. Chen ◽  
B. Gwalani ◽  
E. J. Kautz ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Work Hardening ◽  
Dislocation Motion ◽  
Stacking Fault ◽  
Dislocation Slip ◽  
Simultaneous Increase ◽  
High Entropy Alloy ◽  
High Entropy ◽  
In Situ Neutron Diffraction

AbstractTransformation induced plasticity (TRIP) leads to enhancements in ductility in low stacking fault energy (SFE) alloys, however to achieve an unconventional increase in strength simultaneously, there must be barriers to dislocation motion. While stacking faults (SFs) contribute to strengthening by impeding dislocation motion, the contribution of SF strengthening to work hardening during deformation is not well understood; as compared to dislocation slip, twinning induced plasticity (TWIP) and TRIP. Thus, we used in-situ neutron diffraction to correlate SF strengthening to work hardening behavior in a low SFE Fe40Mn20Cr15Co20Si5 (at%) high entropy alloy, SFE ~ 6.31 mJ m−2. Cooperative activation of multiple mechanisms was indicated by increases in SF strengthening and γ-f.c.c. → ε-h.c.p. transformation leading to a simultaneous increase in strength and ductility. The present study demonstrates the application of in-situ, neutron or X-ray, diffraction techniques to correlating SF strengthening to work hardening.

Defect Structures in Neutron Irradiated 6H-SiC Studied by X-Ray Diffraction Line Profile Analysis

2000 ◽  
Vol 640 ◽  
Author(s):  
C. Seitz ◽  
A. Magerl ◽  
R. Hock ◽  
H. Heissenstein ◽  
R. Helbig
Keyword(s):  
Line Profile ◽  
Correlation Length ◽  
Defect Structure ◽  
Profile Analysis ◽  
Line Profile Analysis ◽  
Defect Structures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Annealing Temperatures ◽  
Diffraction Line Profile

ABSTRACTWe have investigated by x-ray diffraction defect structures in 6H-SiC after neutron irradiation with different fluences and followed by different annealing procedures. An interpretation along a model of Klimanek [1, 4–6] shows, that higher fluences lead to a stronger than linear reduction of the correlation length, whereas higher annealing temperatures correlate with a better recovery of the correlation length. In addition defects of 1st kind created by irradiation are reduced by annealing. We find that annealing changes the character of the defects and it accentuates a defect structure already present in the original samples.

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