The Kirkendall Effect in Solid State Diffusion PhD Thesis

Trefwoorden: metalen en metaallegeringen ; vastestofchemie / diffusie / microstructuur / intermetallische verbindingen / grensvlakverschijnselen ; Kirkendall effect Subject headings: metals and metal alloys ; solid state chemistry / diffusion / microstructure / intermetallic compounds / interfacial phenomena ; Kirkendall effect To my Parents Contents Chapter 1: Introduction 1 1.1 Recent developments in the understanding of the 1 Kirkendall effect 1.2 Motivation of the work and outline of the thesis 6 Chapter 2: Experimental techniques 11 2.1 Preparation of the starting materials (end-members) 11 2.2 Preparation of the diffusion couple 11 2.3 Analysis of the diffusion couple 13 Chapter 3: Bifurcation and trifurcation of the Kirkendall plane 15 3.1 Bifurcation of the Kirkendall plane in a single-phased β-NiAl 15 diffusion layer I. Introduction and statement of the problem 15 II. Selection of β-NiAl as a model system and experimental 16 approach III. Relative mobilities of species and interdiffusion in the β-NiAl 19 intermetallic IV. Velocity curve construction in a single-phased β-NiAl 25 diffusion layer V. Kirkendall effect and morphological development 25 3.2 Bifurcation of the Kirkendall plane in a multilayered multiphase 28 reaction zone: Ag-Zn system I. Interdiffusion and intrinsic diffusion coefficients, and the velocity 28 curve construction II. Kirkendall effect and morphological evolution 29 3.3 Trifurcation of the Kirkendall plane: Ti-Al system 33 I. Interdiffusion and velocity curve construction 33 II. The effect of Kirkendall plane on grain morphology 36 3.4 Concluding remarks 38 Chapter 4: A physico-chemical approach and morphological evolution 41 4.1 Multiphase diffusion growth and morphological developments in 41 the Co-Si system. I. Diffusion based approach 42 II. A physico-chemical approach 43 Contents 4.2 Application of the physico-chemical approach in a system 52 consisting phases with wide homogeneity range. I. A diffusion zone in the Ag-Zn system showing bifurcation of the 53 Kirkendall plane II. A Ti/TiAl 3 diffusion couple showing trifurcation of the 56 Kirkendall plane 4.3 Conclusions 59 Chapter 5: Diffusion studies in the β-NiAl and γ′-Ni 3 Al phase 63 5.1 Studies in the β-NiAl phase 63 I. Interdiffusion coefficients 63 II. Intrinsic diffusion coefficients 67 III. Tracer diffusion coefficients 67 5.2 Studies in the γ′-Ni 3 Al phase 71 I. Experimental results and interdiffusion coefficients 71 II. Determination of the Al tracer diffusivities 74 5.3 Conclusions 77 Chapter 6: Intermetallic growth and Kirkendall effect manifestations in 79 in Cu(Ni)/Sn and Au/Sn diffusion couples 6.1 Solid-state interactions in Cu/Sn binary diffusion couples 80 …