Advanced method for structure-strength-ductility assessment of dispersion-strengthened FCC metals using activation work, mean slip distance and constitutive relation analyses: Decoding the Haasen plot

Saimoto, S.; Diak, B.J.

doi:10.1016/j.msea.2021.142119

Cited by 7 publications

(4 citation statements)

References 40 publications

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“…Using N V = 0 and 5 for 78 and 195 K, respectively, for super-pure Al, results in S for = 14.86 × 10 −5 K −1 compared to S up = 12.9 × 10 −5 K −1 at 78 K, and 2.25 × 10 −5 K −1 to 2.03 × 10 −5 K −1 at 195 K. The model requires that S for > S up . This method to separate the contributing defects that comprise the composite S was applied to the case for nano-sized alumina dispersed in high conductivity Cu and the controlling mechanisms and debris generated were identified in a self-consistent manner [22]. One issue that arises is that ∂S/∂T| τ must be negative, whereas to calculate the modelled S for , E C was kept constant.…”

Section: Experimental Methodsmentioning

confidence: 99%

“…As previously discussed [22], the percolation in the pre-strain regime is highly dependent on the start microstructure and taken to start at the proportional limit, σ0, defined…”

Section: Schematic Analyses Of the Haasen Plot Using Additivity Of 1/νmentioning

confidence: 99%

“…As previously discussed [22], the percolation in the pre-strain regime is highly dependent on the start microstructure and taken to start at the proportional limit, σ 0, defined to occur at 0.02% ε. Nevertheless, for pure metals at 0.2% ε proof stress, it was assumed that the mean slip distance equals the inter-obstacle distance (λ = ), and therefore becomes the origin for dislocation density increase and start of S for as indicated at the intersection of the dashed line with the vertical line at 0.2% ε (see schematic Haasen plot of Figure 3).…”

Section: Schematic Analyses Of the Haasen Plot Using Additivity Of 1/νmentioning

confidence: 99%

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Rate-Controlling Microplastic Processes during Plastic Flow in FCC Metals: Origin of the Variation of Strain Rate Sensitivity in Aluminum from 78 to 300 K

2022

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The thermodynamic response of dislocation intersections with forest dislocations and other deformation products is recorded using the Eyring rate relation wherein the application of shear stress increases the probability of activation at a given strain rate and temperature. The inverse activation volume, 1/ν, can be directly determined by instantaneous strain-rate change and its dependence on flow stress, τ, defines the strain-rate sensitivity, S, through the Haasen plot slope. A linear slope over a large strain interval is observed even for a heterogeneous distribution of obstacles that could be of more than one type of obstacles encountered by the gliding dislocation. It was deduced that ν and τ at each activation site are coordinated by the internal stress resulting in constant activation work (k/S). The stress changes from down-rate changes become larger than that from up-rate changes due to the formation of weaker obstacles, resulting in a composite S, whereas only forest dislocations are detected by the up-change. The additivity of 1/ν was used to separate obstacle species in specially prepared AA1100 and super-pure aluminum from 78 to 300 K. The deduction that repulsive intersection is the rate-controlling process and creates vacancies at each intersection site depending on temperature was validated by observing the pinning and depinning of dislocations via pipe diffusion above 125 K. A new method to separate S for dislocation-dislocation intersections from the intersections with other obstacles and their temperature dependence is presented and validated.

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Section: Experimental Methodsmentioning

confidence: 99%

“…As previously discussed [22], the percolation in the pre-strain regime is highly dependent on the start microstructure and taken to start at the proportional limit, σ0, defined…”

Section: Schematic Analyses Of the Haasen Plot Using Additivity Of 1/νmentioning

confidence: 99%

Section: Schematic Analyses Of the Haasen Plot Using Additivity Of 1/νmentioning

confidence: 99%

See 1 more Smart Citation

Rate-Controlling Microplastic Processes during Plastic Flow in FCC Metals: Origin of the Variation of Strain Rate Sensitivity in Aluminum from 78 to 300 K

2022

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“…The apparent activation distance, d, and work done by the applied stress during thermal activation, W ⇤ , have been used to characterize the obstacles for glide dislocations [32,33]. If l is the average spacing between thermally activatable obstacles, and l is changing with the stress as l = M ↵µb , the apparent activation distance is given as (Eq.11),…”

Section: Kinematics Of Plastic Deformation and Work Hardeningmentioning

confidence: 99%