Physical aging of glasses : the VFT approach / Jacques Rault.

Format:

Book

Author/Creator:

Rault, Jacques.

Series:

Materials science and technologies series.

Materials science and technologies series

Language:

English

Subjects (All):

Glass--Mechanical properties.

Glass.

Glass--Heat treatment.

Enthalpy.

Physical Description:

1 online resource (122 p.)

Edition:

1st ed.

Place of Publication:

New York : Nova Science Publishers, c2009.

Language Note:

English

Summary:

In this book, the author examines the process of ageing in metallic, organic and mineral glasses, all of which evolve similarly with time and approach an equilibrium state. He explores the kinetics of physical ageing, volume, enthalpy and mechanical properties such as creep, stress relaxation, yield stress and modulus.

Contents:

Intro

PHYSICAL AGING OF GLASSES: THE VFT APPROACH

CONTENTS

PREFACE

Chapter 1 INTRODUCTION

Chapter 2 PROPERTIES OF THE DIFFERENT MOTIONS α AND β IN GLASS FORMER MATERIALS

2.1. COOPERATIVITY OF THE β MOTIONS , ORIGIN OF THE VFT LAW

2.2. RELATION BETWEEN VOLUME AND ENTHALPY: THE GRÜNEISEN PARAMETER

2.3. EFFECT OF PRESSURE, RELATION BETWEEN ACTIVATION ENERGY AND ACTIVATION VOLUME

Chapter 3 MODEL OF AGING: THE VFT RELAXATION FUNCTION

3.1. THE EQUIVALENT TEMPERATURE

3.2. INCUBATION AND FINAL RELAXATION TIMES

3.3. THE VFT RELAXATION EQUATION (VFT-RE)

3.4. GENERAL PROPERTIES OF THE VFT-RELAXATION FUNCTIONS (VFT-RF)

3.5. COMPARISON WITH OTHER RELAXATION FUNCTIONS

a) The KWW Relaxation Function

b) The Continuous Distribution of Relaxation Times

Chapter 4 VOLUME AND ENTHALPY RECOVERY

4.1. ISOTHERMAL AGING

4.1.1. Down T-Jump : Contraction

Variation of the Slope kv with Temperature

Stabilisation Domain

Remark

4.1.2. Up T-Jump : Expansion

The α and β Processes in T-Jump Experiments

Conclusion

4.1.3. Memory Effects : The Two Steps T-Jump Experiments

a) Origin of Tmax , the Time to Erase the Thermal History

b) Amplitude ΔVmax of the Memory Effect

c) Variation of tmax with T1 and T2

4.2. NON ISOTHERMAL AGING

4.2.1. Experimental Behaviour

a) Dilatometry

b ) Calorimetry

4.2.2 The Deborah Criteria

A ) Continuous Cooling

B) Continuous Heating

4.2.3. The VFT Relaxation Function

Cooling

Heating

4.2.3. Effect of Aging on the VFT-RF Curves

4.3. EFFECT OF PRESSURE

4.3.1. Isobars and Isotherms V(T,P)

4.3.2. Geometrical Estimation of Tg(P)

4.3.3 The Pressure VFT Law

4.3.4. Deborah Criteria

Chapter 5 MECHANICAL PROPERTIES

5.1. YIELD STRESS.

Example of Application of the Generalized VFT Model

Final Relaxation Time

5.2. CREEP

5.2.1. Short Term Compliance: Horizontal and Vertical Creep Shift Factors

a) Vertical Shift

B) Horizontal Shift Factor log a

Aging Time Dependence

Origin of the Time T*

Stress Dependence

Temperature Dependence

The Correlation Law : n log τ =Constant

5.2.2. Long Term Compliance

5.3. STRESS RELAXATION

The "Classical" Stress Relaxation Method

The "Tickle" Stress Relaxation Method

Remark on Modulus at Fixed Strain

Chapter 6 CONCLUSION

ANNEXE A. THE GRÜNEISEN PARAMETER

ANNEXE B. THE MULTIPLE GLASS TRANSITIONS

CHAIN STEREOREGULARITY

Simple T-jump

Double Down T-Jump

Remark on Physical Aging

STRUCTURAL HETEROGENEITY

REFERENCES

INDEX

Blank Page.

Notes:

Description based upon print version of record.

Includes bibliographical references (p. [107]-110) and index.

Description based on print version record.

ISBN:

1-61668-002-4

OCLC:

853455942