phdindustrialengineering

Lecture: Fundamentals of plastic flow: analysis and modelling

Giuliano Angella

(Istitute CNR-ICMATE)

 Programme

1. Fundamental of plastic deformation: resolved shear stress, gliding and yield criteria.

2. Introduction to dislocations: slip systems; stacking faults energy (SFE) and dislocation structures; athermal gliding; thermal activated gliding; deformation associated to thermal activation; microstructure features relevant to dislocation motion.

3. Strain hardening: phenomenology of strain hardening; single crystal and polycrystals; microstructure features relevant to strain hardening.

4. Analysis of mechanical behavior: time recovery versus strain softening; scaling relationships for flow stress and work hardening; effect of rate and temperature on strain hardening; material scaling.

5. Flow curves and microstructure evolution at low and intermediate temperatures; dynamic recovery and dislocation structures; influence of temperature and strain rate; influence of solute and SFE.

6. Constitutive equations for low temperature deformations: Hollomon-type equations.

7. Constitutive equations related to dislocation density and microstructural parameters: Voce-type equations.

8. Constitutive equations for high temperature deformations: steady-state flow curves.

9. Physical base models of plastic deformation: equations for obstacles controlled plastic flow; models of strain hardening.