## Mechanical metallurgy |

### From inside the book

Results 1-3 of 32

Page 141

The dislocations threading through the active slip plane are often called a

dislocation forest, and this strain-hardening process is referred to as the

intersection of a forest of dislocations. Figure 4-32a shows that dislocation

intersection results in a small step or jog in the dislocation line. Jogs on a

dislocation restrict its motion so that they contribute to strain hardening. Jogs are

also formed by a

another plane which contains ...

The dislocations threading through the active slip plane are often called a

dislocation forest, and this strain-hardening process is referred to as the

intersection of a forest of dislocations. Figure 4-32a shows that dislocation

intersection results in a small step or jog in the dislocation line. Jogs on a

dislocation restrict its motion so that they contribute to strain hardening. Jogs are

also formed by a

**screw dislocation**cross slipping from the primary slip plane toanother plane which contains ...

Page 172

RHS t't Before After Before After Figure 5-21 (a) Intersection of edge and

intersection of two edge dislocations (of either orientation) are able to glide

readily because they lie in the slip planes of the original dislocations. The only

difference between the motion of the jogged dislocation and an ordinary edge

dislocation is that instead of gliding along a single plane, it glides over a stepped

surface. Thus ...

RHS t't Before After Before After Figure 5-21 (a) Intersection of edge and

**screw****dislocation**; (b) intersection of two**screw dislocations**. The jogs produced by theintersection of two edge dislocations (of either orientation) are able to glide

readily because they lie in the slip planes of the original dislocations. The only

difference between the motion of the jogged dislocation and an ordinary edge

dislocation is that instead of gliding along a single plane, it glides over a stepped

surface. Thus ...

Page 173

Since the energy of a dislocation is aGb2 (where a is about 0.5 to 1.0), the energy

of a jog of length b2 in a dislocation of Burgers vector bl is Uj = aGb\b2 (5-25)

where a □» 0.2. The energy of a jog is about 0.5 to 1.0 eV in metals. We have

seen that the most significant dislocation intersection is the case of two

the jogs are able to move readily with their dislocations. The nonconservative

motion of ...

Since the energy of a dislocation is aGb2 (where a is about 0.5 to 1.0), the energy

of a jog of length b2 in a dislocation of Burgers vector bl is Uj = aGb\b2 (5-25)

where a □» 0.2. The energy of a jog is about 0.5 to 1.0 eV in metals. We have

seen that the most significant dislocation intersection is the case of two

**screw****dislocations**where nonconservative jogs are produced. For all other intersectionsthe jogs are able to move readily with their dislocations. The nonconservative

motion of ...

### What people are saying - Write a review

We haven't found any reviews in the usual places.

### Contents

Stress and Strain Relationships for Elastic Behavior | 18 |

from Elastic Strains 213 Strain Energy 214 Anisotropy | 46 |

Metallurgical Fundamentals | 101 |

Copyright | |

15 other sections not shown

### Other editions - View all

### Common terms and phrases

alloy angle annealed ASTM atoms axis behavior billet brittle fracture Burgers vector cold-worked components compression constant crack creep cycles decrease determined diameter direction dislocation line ductile edge dislocation elastic elongation embrittlement energy engineering equation extrusion factor failure fatigue limit fiber Figure flow curve flow stress force forging friction given grain boundaries hot-working hydrostatic increase indentation lattice length load machining martensite material matrix maximum measured mechanical metallurgical Metals Park modulus necking notch occurs particles percent plane strain plane-strain plastic deformation plastic strain pressure produce properties ratio recrystallization reduction region residual stresses rolling screw dislocation shear stress sheet shown in Fig slip plane slip systems Society for Metals specimen steel strain hardening strain rate stress-strain curve structure surface temperature tensile strength tensile stress tension test tensor thickness tool torsion Trans usually velocity workpiece yield strength yield stress