Contents

SUMMARY

PREFACE

INTRODUCTORY NOTE

1. FORMATION OF A CHEMICAL COMPOUND LAYER AT THE INTERFACE OF TWO ELEMENTARY SUBSTANCES

1.1. Description of the kinetics of solid-state heterogeneous reactions

1.2. Reaction diffusion

1.3. Growth of the A_pB_q layer at the expense of diffusion of component B

1.3.1. Critical thickness of the A_pB_q layer with regard to component B

1.3.2. Growth regime of the A_pB_q layer with regard to component B: theoretical definition

1.3.3. Stationary point

1.4. Growth of the A_pB_q layer at the expense of diffusion of components A and B

1.4.1. Critical thickness and growth regime of the A_pB_q layer with regard to component A

1.4.2. General kinetic equation: one compound layer

1.4.3. Separate determination of reaction-diffusion constants

1.5. Linear growth of the Cu₆Sn₅ layer in the copper-tin reaction couple

1.6. Parabolic growth of the AlSb layer in the aluminium-antimony diffusion couple

1.7. Linear-parabolic growth of the SiO₂ layer between silicon and oxygen

1.8. Growth kinetics of the NiBi₃ layer at the nickel-bismuth interface

1.8.1. Experimental details

1.8.2. Intermetallic layer composition

1.8.3. The main diffusing component during the NiBi₃ layer growth

1.8.4. NiBi₃ layer growth kinetics

1.9. Interconnection between the reaction- and self-diffusion coefficient of the components of a chemical compound

1.10. Single compound layer: short conclusions

2. GROWTH KINETICS OF TWO COMPOUND LAYERS BETWEEN ELEMENTARY SUBSTANCES

2.1. Partial chemical reactions at phase interfaces

2.2. A system of differential equations describing the rates of formation of two chemical compound layers

2.3. Initial linear growth of the A_pB_q and A_rB_s layers

2.4. Minimal thickness of the A_rB_s layer necessary for the A_pB_q layer to occur

2.5. Non-linear growth of the A_pB_q layer

2.6. Effect of the critical thickness of the A_pB_q layer with regard to component A on the process of growth of the A_rB_s layer

2.7. Paralinear growth kinetics of two compound layers

2.8. Diffusion controlled growth of the A_pB_q and A_rB_s layers

2.8.1. Late diffusional stage of layer formation: system of differential equations

2.8.2. Late diffusional stage of formation of two compound layers: ratio of their thicknesses

2.8.3. Simultaneous diffusional growth of the Al₃Mg₂ and Al₁₂Mg₁₇ intermetallic layers between aluminium and magnesium

2.9. NiBi: missing or too thin?

2.10. Two compound layers: short conclusions

3. OCCURRENCE OF MULTIPLE COMPOUND LAYERS AT THE A-B INTERFACE

3.1. Chemical reactions at phase interfaces in a multiphase binary system

3.2. A system of differential equations describing the growth process of three chemical compound layers between elementary substances A and B

3.3. Initial linear growth of three compound layers

3.4. Transition from linear to non-linear layer-growth kinetics

3.5. Critical values of compound-layer thicknesses and their influence on layer- growth kinetics

3.6. Diffusional stage of formation of compound layers

3.7. Sequence of compound-layer formation at the A-B interface

3.7.1. Phase-diagram predictions

3.7.2. Thermodynamical predictions

3.7.3. Reasons for the formation of multiple compound layers at the A-B interface

3.8. Formation of intermetallic layers in Ni-Zn and Co-Zn diffusion couples

3.8.1. Ni-Zn and Co-Zn phase diagrams

3.8.2. Materials, specimen preparation and experimental methods

3.8.3. Layer identification

3.8.4. Chemical composition of intermetallic layers

3.8.5. Layer growth kinetics

3.9. Multiple compound layers: short conclusions

4. GROWTH KINETICS OF THE SAME CHEMICAL COMPOUND LAYER IN VARIOUS REACTION COUPLES OF A MULTIPHASE BINARY SYSTEM

4.1. Growth of the A_rB_s layer in the A-B reaction couple

4.2. Growth of the A_rB_s layer in the A_pB_q-B reaction couple

4.2.1. Growth of the A_rB_s layer between A_pB_q and B at the expense of diffusion of only component A

4.2.2. Growth of the A_rB_s layer between A_pB_q and B at the expense of diffusion of both components

4.3. Growth of the A_rB_s layer in the A_pB_q-A_lB_n reaction couple

4.4. Comparison of the growth rates of the A_rB_s layer in various reaction couples of the A-B multiphase binary system

4.5. Duplex structure of the A_rB_s layer

4.6. Chemical compound layer in various reaction couples: short conclusions

5. REACTION-DIFFUSION KINETICS IN SOLID-LIQUID AND SOLID-GAS SYSTEMS

5.1. Main relationships governing dissolution of solids in liquids

5.2. Experimental investigation of the dissolution process of a solid in a liquid

5.2.1. Determination of the saturation concentration

5.2.2. Evaluation of the dissolution-rate constant

5.2.3. Estimation of the diffusion coefficient

5.3. Growth kinetics of the chemical compound layer under conditions of its simultaneous dissolution in the liquid phase

5.4. Growth kinetics of intermetallic layers at the transition metal-liquid aluminium interface

5.4.1. Formation of the Fe₂Al₅ layer between Fe and Al

5.4.2. Occurrence of the MoAl₄ layer between Mo and Al

5.4.3. Formation of intermetallics between Fe-Ni (or Cr) alloys and liquid aluminium

5.5. Peculiarities of kinetic dependences in solid-gas systems

5.5.1. Layer thickness-time relationships

5.5.2. Influence of evaporation on the growth rate of a chemical compound layer

5.5.3. Partial oxidation of chemical compounds

5.6. Reaction-diffusion kinetics in solid-liquid and solid-gas systems: short conclusions

CONCLUDING REMARKS

REFERENCES

Subject Index