A new theory of the anomalous yield stress in l12 alloys

Hirsch, P. B.

doi:10.1080/01418619208201539

Cited by 165 publications

(50 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our experimental setting may be well suited to study dislocation±dislocation cutting and their possible consequences on cross-slip [18,19] and on multiplication mechanisms: it would suffice to make pairs of microindentations at well-controlled respective positions to create, on purpose, intersections between dislocation groups of known characteristics. Such experiments are in progress, but none of the observations reported above seems to have originated from such intersections.…”

Section: Discussionmentioning

confidence: 99%

Non-Planar Slip and Cross-Slip at the Onset of Plastic Deformation in Silicon

Vallino

Jacques

George

2000

phys. stat. sol. (b)

View full text Add to dashboard Cite

Section: Discussionmentioning

confidence: 99%

Non-Planar Slip and Cross-Slip at the Onset of Plastic Deformation in Silicon

Vallino

Jacques

George

2000

phys. stat. sol. (b)

View full text Add to dashboard Cite

“…Once a screw dislocation has cross-slipped and become sessile it forms a barrier (called by K-W a lock) to new dislocations from the source. The details of cross-slip and how the dislocations continue to glide have been elucidated by Sun and Hazzledine [22] and elaborated and extended by Hirsch [23]. The formation of barriers would result in a relatively high WHR.…”

Section: Discussionmentioning

confidence: 99%

The Temperature Dependence of Work-Hardening Rate in Invar Fe-Ni Alloys

Ekinci

Uçar

Çankaya

et al. 2002

phys. stat. sol. (a)

View full text Add to dashboard Cite

show abstract

“…An increase in the dependences ρ str.dis (T ) and W (T ) is accompanied by an increase in the dependence τ * (T ). There are numerous data in publications, which evidence that straightline dislocations are the Kear-Wilsdorf barriers [8][9][10][11][12]. The mobility of screw dislocations decreases with increasing temperature; as a result, the dependence ρ str.dis (T ) increases, and there appear many more Kear-Wilsdorf barriers identified with straightline dislocations in Ni 3 Ge single crystals.…”

mentioning

confidence: 93%

“…Indeed, assuming that γ CSF ≈ γ APB + γ SF , where γ APB ≈ 180 J/m 2 is the APB energy and γ SF ≈ 100 J/m 2 is the stacking fault energy, we obtain γ CSF ≈ 280 J/m 2 . Hence, the width of the superpartial dislocation is very small: r ≈ 2-4 nm [8,11]. Interaction of edge superdislocations with point defects in Ni 3 Ge has some specific features.…”

mentioning

confidence: 98%

Contribution of point defects to the temperature anomaly of the yield stress in single crystals of the Ni3Ge alloy

Abzaev

2007

J Appl Mech Tech Phys

View full text Add to dashboard Cite

The temperature dependence of the yield stress τ * of Ni 3 Ge single crystals is studied. The temperature dependence τ * (T ) in the high-temperature region (above 420 K) is found to be conditioned by thermally activated accumulation of the density of non-screw components of superdislocations. Interaction of point defects with edge dislocations and its effect on the temperature anomaly of the yield stress in Ni 3 Ge single crystals are analyzed. The calculated results are found to agree with experimental data.Single crystals of the Ni 3 Ge alloy display a significant temperature anomaly of the yield stress τ * [1][2][3][4][5]. The characteristics of the flow curves and data on the evolution of dislocation substructures in the course of deformation in Ni 3 Ge single crystals with different test temperatures were analyzed in detail in [2][3][4][5]. It was found that the dependences τ * (T ) are nonmonotonic, and the ascending branch has segments with different intensities of thermal hardening. In the low-temperature region (below 420 K), the increase in the yield stress in the Ni 3 Ge alloy with increasing temperature is caused by formation of Kear-Wilsdorf barriers on the screw components of dislocations. The mechanism of interaction of edge components with point defects and their influence on the yield stress have not been adequately addressed.The goal of the present work was to analyze the mechanism of interaction of edge components of superdislocations with point defects and the influence of this interaction on the increase in the yield stress in Ni 3 Ge single crystals with increasing temperature (at temperatures above 420 K).The method of preparing the samples, mechanical tests, and research of the dislocation structure of Ni 3 Ge single crystals was described in [2,4]. For different values of strain ε, Fig. 1a shows the temperature dependences of the yield stress for Ni 3 Ge single crystals with the directions of the strain axis [001], [139], [4917], [234], and [111].The temperature at which these Ni 3 Ge single crystals are tested exerts a significant effect on the dependence τ * (T ). The ascending branch of the curve τ * (T ) has certain segments characterized by different intensities of thermal hardening. The point T ≈ 420 K separates the low-temperature segment from the high-temperature segment (at T > 420 K). The second segment displays a temperature anomaly of the yield stress, and the maximum on the dependences τ * (T ) (peak temperature T p ≈ 873 K) depends weakly on orientation of the strain axis (Fig. 1a).The study of the evolution of the dislocation substructure in strained Ni 3 Ge single crystals showed that it corresponds to the random and uniform type of substructures [6]. The basic configurations are the straightline and curved superdislocations, dipoles and dipole configurations, and fragments of dislocations [7] in the form of rows of small-radius loops and narrow dipoles. The temperature dependences of the scalar density of dislocations and the density of straightline dislocations ρ str.di...

show abstract

A new theory of the anomalous yield stress in l12 alloys

Cited by 165 publications

References 0 publications

Non-Planar Slip and Cross-Slip at the Onset of Plastic Deformation in Silicon

Non-Planar Slip and Cross-Slip at the Onset of Plastic Deformation in Silicon

The Temperature Dependence of Work-Hardening Rate in Invar Fe-Ni Alloys

Contribution of point defects to the temperature anomaly of the yield stress in single crystals of the Ni3Ge alloy

Contact Info

Product

Resources

About