Quantitative analysis of solution hardening in selected copper alloys

Wille, Th.; Gieseke, Walter; Schwink, Ch.

doi:10.1016/0001-6160(87)90267-7

Cited by 68 publications

(33 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Equation [5] showed that the value obtained for the activation energy for dislocation glide, 98 ± 27 kJ mol À1 (see footnote à ), is compatible (within experimental accuracy) with data for the activation energy for the glide of dislocations (109 to 130 kJ mol À1 [47] ), as holds for the powder specimens.…”

Section: Dominant Mechanisms Of the Transformationsupporting

confidence: 63%

“…pct), i.e., 109 to 130 kJ mol À1 . [47] (d) The activation energy of overcoming obstacles by gliding dislocations, without the aid of external stress, can be given by Q ¼ bN A l 0 b j j 3 ; where N A is the Avogadro constant; l 0 is the shear modulus (due to shortage of data for Cu(Ge), here taken as for pure Cu at 300 K (27°C) (=4.21 9 10 10 N m 2 ) [32] ); b j j is the length of the Burgers vector (~2.5 9 10 À10 m); and b is a constant that defines the magnitude of the resistance to glide. [32] From the here obtained value for the activation energy for glide of dislocations, 112.0 ± 2.8 kJ mol À1 , the constant b was then found to be equal to~0.3 which indicates a medium resistance to glide, as typical for fcc metals (which have relatively low lattice resistance), and as generally due to defects or small precipitates.…”

Section: Dominant Mechanisms Of the Transformationmentioning

confidence: 99%

See 1 more Smart Citation

Kinetics of the fcc → hcp Phase Transformation in Cu-Ge Solid Solutions Upon Isothermal Aging

Polatidis

Zotov

Bischoff

et al. 2017

Metall Mater Trans A

View full text Add to dashboard Cite

The kinetics of the f-phase formation from a supersaturated a-Cu(Ge) solid solution (i.e., transformation from the fcc crystal structure to the hcp crystal structure) containing 10.8 at. pct Ge [at isothermal temperatures of 573 K, 613 K, and 653 K (300°C, 340°C, and 380°C)] were studied by X-ray diffraction (XRD) for phase fraction determination. Both in situ and ex situ annealing experiments were performed. The transformation kinetics were modeled on the basis of a versatile modular model. The transformation kinetics complied with a site-saturation nucleation mode and strongly anisotropic interface-controlled growth mode in association with a corresponding impingement mode: diffusion of Ge (towards the stacking faults, SFs) does not control the transformation rate. Transmission electron microscopy (TEM) investigations showed that segregation of Ge at the stacking faults (SFs) takes place (relatively fast) prior to the structural transformation (fcc fi hcp).

show abstract

Section: Dominant Mechanisms Of the Transformationsupporting

confidence: 63%

Section: Dominant Mechanisms Of the Transformationmentioning

confidence: 99%

Kinetics of the fcc → hcp Phase Transformation in Cu-Ge Solid Solutions Upon Isothermal Aging

Polatidis

Zotov

Bischoff

et al. 2017

Metall Mater Trans A

View full text Add to dashboard Cite

show abstract

“…Examples of such fittings are shown in Fig. 5 for the Cu-Al [44], Cu-Ge, Cu-Mn [51] and Ag-Al [41] systems. The fitted parameters are summarized in Table 1.…”

Section: Dilute Limitmentioning

confidence: 99%

“…Nonetheless, the simplicity of the Friedel model -it contains just a few physically-based parameters -has led to continued applications of the model concepts. In particular, when the Friedel model based on pinning by individual solute atoms has failed to quantitatively explain experiments, researchers have postulated the existence of solute "clusters" as the operative pinning points within a Friedel-type model [51,52,53]. These experiments are, however, well-interpreted in terms of the Labusch-type models.…”

Section: Introductionmentioning

confidence: 99%

Solute strengthening in random alloys

et al. 2017

View full text Add to dashboard Cite

Random solid solution alloys are a broad class of materials that are used across the entire spectrum of engineering metals, whether as stand-alone materials (e.g. Al-5xxx alloys) or as the matrix in precipitatestrengthening materials (e.g. Ni-based superalloys). As a result, the mechanisms of, and prediction of, strengthening in solid solutions has a long history. Many concepts have been developed and important trends identified but predictive capability has remained elusive. In recent years, a new theory has been developed that builds on one historical model, the Labusch model, in important ways that lead to a well-defined model valid for random solutions with arbitrary numbers of components and compositions. The new theory uses first-principles-computed solute/dislocation interaction energies as input, from which specific predictions emerge for the yield strength and activation volume as a function of alloy composition, temperature, and strain-rate. Being a general model for materials that otherwise have a low Peierls stress, it has broad application and has been successfully applied to Al-X alloys, Mg-Al, twinning in Mg alloys, and recently fcc High-Entropy Alloys. Here, the new theory is presented in a general and systematic manner. Approximations and limiting cases that reduce the complexity and facilitate understanding are introduced, and help relate the new model to various physical features present among the historical array of models. The quantitative predictions of the model in the various materials above is then demonstrated.

show abstract

“…For instance, HallPetch effects [2], anomalous athermal stresses [6], solute clustering [6,7], and/or unphysical dislocation/solute interactions [8][9][10], have been invoked to justify deviations between various solute strengthening theories [8][9][10][11][12] and experimental data. However, such reasonable attempts to rationalize experimental data obfuscate the relevant underlying mechanisms.…”

Section: Introductionmentioning

confidence: 99%

Thermally-activated flow in nominally binary Al–Mg alloys

Leyson

2016

Scripta Materialia

View full text Add to dashboard Cite

The temperature-dependent flow behavior in nominally binary Al-Mg alloys measured recently [1,2] is interpreted in the context of a parameter-free solute strengthening model. The recent measurements show consistently higher strengths as compared to literature data on true binary Al-Mg alloys, which is attributed to the presence of Fe in the nominally binary Al-Mg. Using the Fe concentration as a single fitting parameter, the model predictions for the newer materials when treated as Al-Mg-(Fe) alloys agree with experiments to the same degree as obtained for the true binary Al-Mg. The model then predicts the activation volume in good agreement with experimental trends.In interpreting experimental data for strengths of Al alloys, multiple mechanisms operating simultaneously are often invoked because the application of simple or ad-hoc theories does not explain observed trends. For instance, HallPetch effects [2], anomalous athermal stresses [6], solute clustering [6,7], and/or unphysical dislocation/solute interactions [8][9][10], have been invoked to justify deviations between various solute strengthening theories [8][9][10][11][12] and experimental data. However, such reasonable attempts to rationalize experimental data obfuscate the relevant underlying mechanisms. Here we re-examine recent data on a set of nominally binary Al-Mg alloys first reported by Jobba et al.[1] and then further analyzed by Niewczas et al. [2]. We show that the finitetemperature flow behavior of the alloys in these works can be explained by the inclusion of a low concentration of Fe without the need to invoke any other additional mechanisms.The solute strengthening model was developed in Refs. [13,14] and only key points are summarized here. When moving through a random field of solutes with concentration c, an initially straight dislocation can lower its energy by bowing into regions containing favorable solute configurations and bowing away from regions with unfavorable solute configurations. The segments thus reside in favorable solute configurations and require stress-and thermally-driven activation to escape and move to the next favorable environment. The characteristic energy barrier ∆E b for pinned segments is ∆E b = 1.22

show abstract

Quantitative analysis of solution hardening in selected copper alloys

Cited by 68 publications

References 53 publications

Kinetics of the fcc → hcp Phase Transformation in Cu-Ge Solid Solutions Upon Isothermal Aging

Kinetics of the fcc → hcp Phase Transformation in Cu-Ge Solid Solutions Upon Isothermal Aging

Solute strengthening in random alloys

Thermally-activated flow in nominally binary Al–Mg alloys

Contact Info

Product

Resources

About