scholarly journals Study on Influence of a State of Dopants on Dislocation-Dopant Ions Interaction in Annealed Crystals

2021 ◽  
Author(s):  
Yohichi Kohzuki
Keyword(s):  
Plastic Deformation ◽  
Strain Rate ◽  
Low Temperatures ◽  
High Stress ◽  
Rate Sensitivity ◽  
Influential Factor ◽  
Combination Method ◽  
Ultrasonic Oscillations ◽  
Flow Parameters ◽  
Critical Temperature Tc

Combination method of strain-rate cycling tests and application of ultrasonic oscillations was conducted for KCl:Sr2+ (0.035, 0.050, 0.065 mol.% in the melt) single crystals at low temperatures. The measurement of strain-rate sensitivity (λ) of flow stress under the application of ultrasonic oscillatory stress provides useful information on the interaction between a mobile dislocation and impurities (Sr2+ ions) during plastic deformation and the variation of λ with stress decrement (Δτ) due to oscillation has stair-like shape: The first plateau place ranges below the first bending point (τp1) at low stress decrement and the second one extends from the second bending point (τp2) at high stress decrement. The value of λ decreases with the Δτ between the two bending points. The τp1 is considered to represent the effective stress due to impurities when a dislocation begins to break-away from the impurities with the help of thermal activation during plastic deformation. Annealing the impure crystal by heat treatment, τp1 decreases obviously at low temperature and the critical temperature Tc, at which τp1 is zero, also becomes slightly smaller. Furthermore, it was investigated whether a change in the state of a small amount of impurities has an influential factor of the flow parameters (e.g., the activation energy, the density of forest dislocations) from the data analyzed in terms of Δτ vs. λ curve.

Activation volume and strain rate sensitivity in plastic deformation of nanocrystalline Ti

2013 ◽  
Vol 228 ◽  
pp. S254-S256 ◽  
Author(s):  
F. Wang ◽  
B. Li ◽  
T.T. Gao ◽  
P. Huang ◽  
K.W. Xu ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
Activation Volume ◽  
Rate Sensitivity

Strain Rate Sensitivity of Commercial Aluminum Alloys

2019 ◽  
Author(s):  
R.C. Picu
Keyword(s):  
Plastic Deformation ◽  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
Solid Solutions ◽  
Elevated Temperatures ◽  
Rate Sensitivity ◽  
Solute Diffusion ◽  
Rate Dependent ◽  
Ultrafine Grained ◽  
Using Data

This article presents a review of the strain rate-dependent mechanical behavior of aluminum and its commercial alloys. The importance of strain rate sensitivity (SRS) stems from its relation with ductility and formability. Plastic deformation is stable and localization less likely in alloys with higher SRS. After discussing the basic formulation used to interpret experimental data, the methods used to measure the SRS parameter are presented. This is followed by a brief review of the main mechanisms that render the flow stress sensitive to the deformation rate, including mechanisms leading to positive and negative SRS. The generic dependence of the SRS parameter on the strain, temperature, and strain rate are further presented using data for pure Al. The effect of alloying is analyzed in the context of solid solutions and precipitated commercial alloys. Results on solid solutions are discussed separately at low and elevated temperatures in order to evidence the role of solute diffusion on SRS. This article ends with a brief discussion of the grain size dependence of SRS, with emphasis on recent efforts to produce nanocrystalline and ultrafine-grained materials by severe plastic deformation.

An Experimental Evaluation on Change in Impedance of TRIP Steel Subjected to Plastic Deformation at Various Strain Rates

2013 ◽  
Vol 535-536 ◽  
pp. 445-448 ◽  
Author(s):  
Daiki Inoshita ◽  
Shiro Yamanaka ◽  
Takeshi Iwamoto
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Martensitic Transformation ◽  
Strain Rate ◽  
Trip Steel ◽  
Rate Sensitivity ◽  
Volume Resistivity ◽  
Strain Rates ◽  
Trip Steels ◽  
The Relationship

For automotive industries, weight of an automobile can be reduced if TRIP steel which has excellent mechanical properties dominated by strain-induced martensitic transformation (SIMT) can be applied to shock absorption members. However, strain rate sensitivity of TRIP steels has not been fully understood because a relationship between a strain rate and an amount of martensite produced by SIMT is still unclear. In previous studies, volume resistivity and impedance have been measured to obtain information on the amount of produced martensite, however, these studies have not been succeeded to clarify the relationship. Here, by focusing a property that martensite shows ferromagnetism, it is attempted that impedance of TRIP steel is measured at various strain rates during the deformation by using prototype coil and circuits.

Strain-Rate Sensitivity and Failure Peculiarities in Compression of the Nanocrystalline Ni-20 Pct Fe Alloy at Low Temperatures

2010 ◽  
Vol 41 (4) ◽  
pp. 848-853 ◽  
Author(s):  
E.D. Tabachnikova ◽  
A.V. Podolskiy ◽  
V.Z. Bengus ◽  
S.N. Smirnov ◽  
H. Li ◽  
...  
Keyword(s):  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
Low Temperatures ◽  
Rate Sensitivity
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