Mechanical Behaviour of Materials

Dr.-Ing. 郭 瑞 昭

Chapter 16 Creep

Introduction to creep

Creep : time-dependent plastic deformation at high temperature

Effect of temperature and stress on creep

Creep mechanism: Nabarro-Herring creep

The creep occurs by diffusion through the lattice

LLHND

dA 2

. σε =

−�

Creep mechanism: Coble creep

The creep occurs by diffusion along grain boundaries

gbGC Dd

A 3

. σε =�

Creep mechanism: dislocation movement

The creep occurs by diffusion along grain boundaries

mSA σε =�

.

Deformation Mechanism Maps

Alloys for high temperature applications