Chapter 16 Creep - NCKU

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Mechanical Behaviour of Materials Dr.-Ing. Chapter 16 Creep

Transcript of Chapter 16 Creep - NCKU

Page 1: Chapter 16 Creep - NCKU

Mechanical Behaviour of Materials

Dr.-Ing. 郭 瑞 昭

Chapter 16 Creep

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Introduction to creep

Creep : time-dependent plastic deformation at high temperature

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Effect of temperature and stress on creep

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Creep mechanism: Nabarro-Herring creep

The creep occurs by diffusion through the lattice

LLHND

dA 2

. σε =

−�

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Creep mechanism: Coble creep

The creep occurs by diffusion along grain boundaries

gbGC Dd

A 3

. σε =�

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Creep mechanism: dislocation movement

The creep occurs by diffusion along grain boundaries

mSA σε =�

.

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Deformation Mechanism Maps

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Alloys for high temperature applications