Metals Strengthening (2)

Home

Get App

Create

Strengthening Mechanisms (4)
- Grain size reduction
- Solid solution strengthening
- Precipitate Strengthening
- Cold work /strain hardening
Annealing (heat treatment) Effects on deformation and strength (3)
- Recovery
- Recrystallization
- Grain Growth
Solid solutions (a) stress field
Impurity atoms ____ the lattice and generate ____
_____ can produce a _____ to dislocation motion
- Impurity atoms distort the lattice and generate stress
- Stress can produce a barrier to dislocation motion
- Think of a dislocation gliding into vicinity of solute atom
Solid solutions (b) solute drag
____ impurities tend to _____ at dislocations
Reduce ____ of dislocation there increases ____
- Small impurities tend to concentrate at dislocations
- Reduce mobility of dislocation there for increase strenth
Cold work dislocations
Dislocations _______with on another during cold work
________ becomes more difficult
- Dislocations entangle with on another during cold work
- Dislocation motion becomes more difficult
Dislocation density equation

Total dislocation length / unit volume
As cold work is increased:
Yield strength _______
Tensile strength ________
Ductility ________
- Increases
- Increases
- Decreases
What is the tensile strength and ductiliy after cold working?
%CW equation

Pi*r0^2 - Pi ra^2/ (Pi *r0^2) x 100
Stage 1 of annealing :recovery
_____ T treatments - Dislocation density ____
Mechanism : Annnihilation _____ dislocation desntiy
- Low
- Decrease
- reduce
Recrystallisation
- Occurs at higher temperature than recovery
- New grains are formed that have lower dislocation density
- are generally smaller
- consume cold work grains
Grain growth
_____ temperatures and _____ time than recrystallisaion

Larger grains consume smaller grains

Author

Marciaho

269868

Card Set

Metals Strengthening (2)

Description

Metals Strengthening (2)

Updated

2014-04-09T05:07:21Z

Show Answers