The influence of aluminium content to the stacking fault energy in Fe-Mn-Al-C alloy system

1990 ◽  
Vol 25 (3) ◽  
pp. 1821-1823 ◽  
Author(s):  
W. S. Yang ◽  
C. M. Wan
Keyword(s):  
Alloy System ◽  
Stacking Fault ◽  
Stacking Fault Energy ◽  
Aluminium Content

GRAIN-SIZE DEPENDENCE OF FRACTURE IN COPPER–ALUMINIUM ALLOYS EMBRITTLED BY MERCURY

1967 ◽  
Vol 45 (2) ◽  
pp. 1235-1249 ◽  
Author(s):  
F. W. J. Pargeter ◽  
M. B. Ives
Keyword(s):  
Aluminium Alloys ◽  
Cellular Network ◽  
Size Dependence ◽  
Network Formation ◽  
Pure Copper ◽  
Stacking Fault ◽  
Stacking Fault Energy ◽  
Aluminium Content ◽  
Α Phase ◽  
Stacking Fault Energies

Polycrystalline specimens of α-phase copper–aluminium alloys of varying composition, amalgamated with mercury, have been deformed in tension in a soft tensile machine. In all cases, brittle intergranular failure occurred at stresses and strains below those required for fracture in air, the degree of embrittlement increasing with increasing aluminium content. The alloys having stacking-fault energies less than '~8 erg/cm2 were found to obey quite well the Petch–Stroh relation:[Formula: see text]The other alloys showed deviations from this relation which became more marked with increasing stacking-fault energy. Values of the fracture energy, varying from ~48 erg/cm2 for pure copper to ~470 erg/cm2 for Cu −8 wt.% Al, have been obtained for all of the alloys. These values are only applicable for relatively small grain sizes.The deviation from the Petch–Stroh relation in the high stacking-fault energy alloys is thought to be due to their tendency to show cross-slip and cellular-network formation, rather than coplanar arrays of dislocations as required by the Stroh model. The low stacking-fault energy alloys typically show well-defined pileups and so obey the Petch–Stroh relations, as expected.

Studies on Extended Dislocation Nodes in a ζ-Phase Silver-Tin Alloy

1967 ◽  
Vol 25 ◽  
pp. 304-305
Author(s):  
L. K. Ives ◽  
A. W. Ruff
Keyword(s):  
Alloy System ◽  
Solute Concentration ◽  
Phase Region ◽  
Stacking Fault ◽  
Stacking Fault Energy ◽  
Cubic Phase ◽  
Face Centered Cubic ◽  
Two Phase ◽  
The Face ◽  
Extended Dislocation

A determination of the intrinsic stacking fault energy as a function of composition has been previously reported for the face-centered-cubic phase in the silver-tin alloy system. The method involved direct measurements on extended dislocation nodes observed by transmission electron microscopy in alloys containing from 0 to 7.8 at.% tin. The stacking fault energy γ was found to decrease from a value of 22.8 erg/cm3 for silver to 4.2 erg/cm2 for the 7.8 at.%. alloy. Figure 1 shows the phase diagram for this system. At room temperature, the α-phase limit occurs at about 8.5 to 9 at.%. tin. A two-phase region extends to approximately 11.5 at.% followed by the ζ- Ag Sn phase region which exists to about 17 at.% tin. A series of hexagonal ζ alloys of various compositions are presently under study to determine the variation of the stacking fault energy with composition. Preliminary results indicate that the stacking fault energy increases with increasing solute concentration in the ζ-phase region. Extended dislocation nodes have been observed in all the ζ alloys, together with extended ribbons in the dilute alloys. This paper will consider only the results obtained on the most dilute alloy (12 at.% tin) and compare them with the a-phase results.

On effects of non-systematic reflections on weak-beam images of partial dislocations

1991 ◽  
Vol 49 ◽  
pp. 688-689
Author(s):  
K. Z. Botros ◽  
S. S. Sheinin
Keyword(s):  
High Precision ◽  
Stacking Fault ◽  
Important Application ◽  
Stacking Fault Energy ◽  
Sharp Peak ◽  
Weak Beam ◽  
Partial Dislocations ◽  
Deviation Parameter ◽  
Beam Diffraction

The main features of weak beam images of dislocations were first described by Cockayne et al. using calculations of intensity profiles based on the kinematical and two beam dynamical theories. The feature of weak beam images which is of particular interest in this investigation is that intensity profiles exhibit a sharp peak located at a position very close to the position of the dislocation in the crystal. This property of weak beam images of dislocations has an important application in the determination of stacking fault energy of crystals. This can easily be done since the separation of the partial dislocations bounding a stacking fault ribbon can be measured with high precision, assuming of course that the weak beam relationship between the positions of the image and the dislocation is valid. In order to carry out measurements such as these in practice the specimen must be tilted to "good" weak beam diffraction conditions, which implies utilizing high values of the deviation parameter Sg.

Structural features and strength behavior of TRIP/TWIP steels

2020 ◽  
pp. 5-18
Author(s):  
D. V. Prosvirnin ◽  
◽  
M. S. Larionov ◽  
S. V. Pivovarchik ◽  
A. G. Kolmakov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Thermomechanical Processing ◽  
Maximum Load ◽  
Structural Features ◽  
Stacking Fault ◽  
Stacking Fault Energy ◽  
Structural And Functional Properties ◽  
Twip Steels ◽  
The Creation

A review of the literature data on the structural features of TRIP / TWIP steels, their relationship with mechanical properties and the relationship of strength parameters under static and cyclic loading was carried out. It is shown that the level of mechanical properties of such steels is determined by the chemical composition and processing technology (thermal and thermomechanical processing, hot and cold pressure treatment), aimed at achieving a favorable phase composition. At the atomic level, the most important factor is stacking fault energy, the level of which will be decisive in the formation of austenite twins and / or the formation of strain martensite. By selecting the chemical composition, it is possible to set the stacking fault energy corresponding to the necessary mechanical characteristics. In the case of cyclic loads, an important role is played by the strain rate and the maximum load during testing. So at high loading rates and a load approaching the yield strength under tension, the intensity of the twinning processes and the formation of martensite increases. It is shown that one of the relevant ways to further increase of the structural and functional properties of TRIP and TWIP steels is the creation of composite materials on their basis. At present, surface modification and coating, especially by ion-vacuum methods, can be considered the most promising direction for the creation of such composites.

scholarly journals A theoretical calculation of stacking fault energy of Ni alloys: The effects of temperature and composition

2021 ◽  
Vol 191 ◽  
pp. 110326
Author(s):  
Mohammad S. Dodaran ◽  
Shengmin Guo ◽  
Michael M. Khonsari ◽  
Nima Shamsaei ◽  
Shuai Shao
Keyword(s):  
Theoretical Calculation ◽  
Stacking Fault ◽  
Stacking Fault Energy ◽  
Ni Alloys ◽  
Effects Of Temperature
Sign in / Sign up

Export Citation Format

Share Document