Stacking Fault Energy, Dislocation Density, and Twin Fault Probability Determined by Neutron Diffraction Peak Profile Analysis in CrCoNi Based Medium Entropy Alloys

2019 ◽  
Author(s):  
Wanchuck Woo ◽  
Muhammad Naeem ◽  
Jae-Suk Jeong ◽  
Stefanus Harjo ◽  
Takuro Kawasaki ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Neutron Diffraction ◽  
Profile Analysis ◽  
Stacking Fault ◽  
Diffraction Peak ◽  
Stacking Fault Energy ◽  
Fault Probability ◽  
Twin Fault

scholarly journals Characterization of Dislocation Rearrangement in FCC Metals during Work Hardening Using X-ray Diffraction Line-Profile Analysis

2020 ◽  
Vol 4 (4) ◽  
pp. 36
Author(s):  
Koutarou Nakagawa ◽  
Momoki Hayashi ◽  
Kozue Takano-Satoh ◽  
Hirotaka Matsunaga ◽  
Hiroyuki Mori ◽  
...  
Keyword(s):  
Grain Size ◽  
Dislocation Density ◽  
Line Profile ◽  
Cell Walls ◽  
Tensile Deformation ◽  
Profile Analysis ◽  
Stacking Fault ◽  
Stacking Fault Energy ◽  
Line Profile Analysis ◽  
Fcc Metals

Multiplication and rearrangement of dislocations in face-centered cubic (FCC) metals during tensile deformation are affected by grain size, stacking fault energy (SFE), and solute elements. X-ray diffraction (XRD) line-profile analysis can evaluate the dislocation density (ρ) and dislocation arrangement (M) from the strength of the interaction between dislocations. However, the relationship between M and ρ has not been thoroughly addressed. In this study, multiplication and rearrangement of dislocations in FCC metals during tensile deformation was evaluated by XRD line-profile analysis. Furthermore, the effects of grain size, SFE, and solute elements on the extent of dislocation rearrangement were evaluated with varying M values during tensile deformation. M decreased as the dislocation density increased. By contrast, grain size and SFE did not exhibit a significant influence on the obtained M values. The influence of solute species and concentration of solute elements on M changes were also determined. In addition, the relationship between dislocation substructures and M for tensile deformed metals were also explained. Dislocations were loosely distributed at M > 1, and cell walls gradually formed by gathering dislocations at M < 1. While cell walls became thicker with decreasing M in metals with low stacking fault energy, thin cell walls with high dislocation density formed for an M value of 0.3 in metals with high stacking fault energy.

scholarly journals Improved Hardness and Thermal Stability of Nanocrystalline Nickel Electrodeposited with the Addition of Cysteine

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2254
Author(s):  
Tamás Kolonits ◽  
Zsolt Czigány ◽  
László Péter ◽  
Imre Bakonyi ◽  
Jenő Gubicza
Keyword(s):  
Thermal Stability ◽  
Grain Size ◽  
Dislocation Density ◽  
Nickel Sulfate ◽  
Fault Probability ◽  
Nanocrystalline Nickel ◽  
Twin Fault ◽  
Cysteine Content ◽  
Heating Up ◽  
Thermal Stability Of

Experiments were conducted for the study of the effect of cysteine addition on the microstructure of nanocrystalline Ni films electrodeposited from a nickel sulfate-based bath. Furthermore, the thermal stability of the nanostructure of Ni layers processed with cysteine addition was also investigated. It was found that with increasing cysteine content in the bath, the grain size decreased, while the dislocation density and the twin fault probability increased. Simultaneously, the hardness increased due to cysteine addition through various effects. Saturation in the microstructure and hardness was achieved at cysteine contents of 0.3–0.4 g/L. Moreover, the texture changed from (220) to (200) with increasing the concentration of cysteine. The hardness of the Ni films processed with the addition of 0.4 g/L cysteine (∼6800 MPa) was higher than the values obtained for other additives in the literature (<6000 MPa). This hardness was further enhanced to ∼8400 MPa when the Ni film was heated up to 500 K. It was revealed that the hardness remained as high as 6000 MPa even after heating up to 750 K, while for other additives, the hardness decreased below 3000 MPa at the same temperature.

Neutron Diffraction Profile Analysis to Determine Dislocation Density and Grain Size for Drawn Steel Wires

2007 ◽  
Vol 539-543 ◽  
pp. 2281-2286 ◽  
Author(s):  
S. Ryufuku ◽  
Yo Tomota ◽  
Y. Shiota ◽  
T. Shiratori ◽  
Hiroshi Suzuki ◽  
...  
Keyword(s):  
Grain Size ◽  
Dislocation Density ◽  
Neutron Diffraction ◽  
Profile Analysis ◽  
Strengthening Mechanism ◽  
Point Of View ◽  
Diffraction Profile ◽  
Petch Relation ◽  
Steel Wires ◽  
Carbon Concentrations

Dislocation density and crystallite size of steel wires with various carbon concentrations and drawing strains were determined by profile analyses for neutron diffraction profiles. The density is found to increase while the size decreases with increasing of carbon concentration and/or drawing strain. Both of the Bailey-Hirsch relation and Hall-Petch relation hold for the present results to suggest that these two are not independent., i.e., indicating an identical strengthening mechanism from a different point of view.

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