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Article
Solidification of Ni-Re Peritectic Alloys
Differential thermal analysis (DTA) and microstructural and microprobe measurements of DTA and as-cast Ni-Re alloys with compositions between 0.20 and 0.44 mass fraction Re provide information to resolve diffe...
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Article
Interdiffusion in the Ni-Re System: Evaluation of Uncertainties
Diffusion couple experiments between Ni and Re at 1200 and 1350 °C were performed. These experiments established the limits of the two-phase FCC + HCP region. No intermediate phase was observed at these temper...
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Article
Analytical Derivation of the Sauer-Freise Flux Equation for Multicomponent Multiphase Diffusion Couples with Variable Partial Molar Volumes
The well-known Sauer-Freise flux equation is derived analytically for the general case of a multiphase, multicomponent diffusion couple with variable molar volume. Discontinuities in concentration versus dista...
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Article
Diffusion in FCC Co-rich Co-Al-W Alloys at 900 and 1000 °C
Diffusion couple experiments between various Co-rich face centered cubic (FCC) alloys in the Co-W-Al ternary system have been conducted at 900 and 1000 °C. Diffusion coefficients have been extracted for the Co...
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Article
Microstructural Studies of Multiphase (Zr, Ti)(V, Cr, Mn, Co, Ni)2 Alloys for NiMH Negative Electrodes
The solidification microstructures of six Laves-based (Zr, Ti)(TM, Ni)2 alloys (TM= V, Cr, Mn, Co) intended for use as novel negative electrodes in Ni-metal hydride batteries were studied here; these alloys often...
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Article
Diffusion Parameters and Growth Mechanism of Phases in the Cu-Sn System
The tracer diffusion coefficients of the elements as well as the integrated interdiffusion coefficients are determined for the Cu3Sn and Cu6Sn5 intermetallic compounds using incremental diffusion couples and Kirk...
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Article
Effect of current density and electrolyte concentration on hillock growth from pure bright Sn electrodeposits
The effect of current density and Sn methane sulfonate concentration on hillock density, columnar grain size, crystallographic texture, and residual stress of bright Sn electrodeposits is measured. Correlation...
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Article
Examination of Multiphase (Zr,Ti)(V,Cr,Mn,Ni)2 Ni-MH Electrode Alloys: Part II. Solid-State Transformation of the Interdendritic B2 Phase
Solidification microstructure of multicomponent (Zr,Ti)-Ni-(V,Cr,Mn,Co) alloys intended for use as negative electrodes in Ni-metal hydride (Ni-MH) batteries was studied in Part I of this series of articles. Pa...
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Article
Examination of Multiphase (Zr,Ti)(V,Cr,Mn,Ni)2 Ni-MH Electrode Alloys: Part I. Dendritic Solidification Structure
The solidification microstructures of three nine-element Zr-Ni–based AB2 type C14/C15 Laves hydrogen storage alloys are determined. The selected compositions represent a class of alloys being examined for usage a...
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Article
Open AccessBending of a Bimetallic Beam Due to the Kirkendall Effect
The time-dependent bending of single-phase and two-phase bimetal strips due to interdiffusion is computed. The model couples simple beam theory and diffusion with bending due to the creation and/or annihilatio...
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Article
Hillock and Whisker Growth on Sn and SnCu Electrodeposits on a Substrate Not Forming Interfacial Intermetallic Compounds
Intermetallic compound (IMC) formation at the interface between the tin (Sn) plating and the copper (Cu) substrate of electronic components has been thought to produce compressive stress in Sn electrodeposits ...
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Article
Numerical modeling of diffusion-induced deformation
We present a numerical approach to modeling the deformation induced by the Kirkendall effect in binary alloys. The governing equations for isothermal binary diffusion are formulated with respect to inert marke...
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Article
Observed correlation of Sn oxide film to Sn whisker growth in Sn-Cu electrodeposit for Pb-free solders
Localized cracking of surface oxide has been proposed as a necessary step in the nucleation of Sn whiskers in Sn electrodeposited films. To evaluate the effects of the oxide film on Sn whisker growth, a bright...
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Chapter
Examination of Multicomponent Diffusion Between two Ni-Base Superalloys
The interdiffusion at 1293 °C between two multicomponent Ni-base superalloys, René-N4 and Ren6-N5, was assessed by measuring the composition vs. distance curves and by comparing the measured curves to predicti...
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Article
Accurately determining eutectic compositions: The Sn-Ag-Cu ternary eutectic
Determining an accurate eutectic composition is more difficult than determining the corresponding eutectic temperature, a fact that was demonstrated in this study using a lead-free solder: the tin-rich Sn-Ag-C...
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Article
Electron backscattered diffraction and energy dispersive X-ray spectroscopy study of the phase NiSn4
Electron backscattered diffraction (EBSD) and energy dispersive X-ray spectroscopy (EDS) have been performed on a plate-shaped phase formed through the reaction of Sn and Ni. The phase is formed during extende...
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Article
Last-stage solidification of alloys: Theoretical model of dendrite-arm and grain coalescence
Hot tearing in castings is closely related to the difficulty of bridging or coalescence of dendrite arms during the last stage of solidification. The details of the process determine the temperature at which a...
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Chapter and Conference Paper
Last Stage Solidification of Alloys: A Theoretical Study of Dendrite Arm and Grain Coalescence
Solidification of metallic alloys has been extensively studied (dendrite tip kinetics, microsegregation, coarsening of dendrite arms, etc.) but surprisingly, in the absence of eutectic reactions (i.e., low con...
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Article
On differential thermal analyzer curves for the melting and freezing of alloys
Using a heat-flow model of a differential thermal analyzer and thermal characteristics obtained by fitting experimental results for a pure metal, the response of the differential thermal analyzer is modeled fo...
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Article
Mechanism of fillet lifting in Sn-Bi alloys
The probability of fillet lifting in through-hole solder joints was determined for a series of seven binary Sn-Bi solders with Bi mass contents between 26% and 65%. A 20-pin ceramic dual inline package was sol...
