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Displaying 26 - 50 of 160

Effect of Phase Change and Solute Diffusion on Spreading on a Dissolving Substrate

October 1, 2010
Author(s)
Walter Villanueva, William J. Boettinger, James A. Warren, Gustav Amberg
Dissolutive wetting is investigated numerically using a diffuse-interface model that incorporates fluid flow, solute diffusion, and phase change. A range of materials parameters are investigated that: 1) permits recovery of the hydrodynamic limit by

Examination of Multiphase (Zr,Ti)(V,Cr,Mn,Ni)2 Ni-MH Electrode Alloys. Part 2: Solid-State Transformation of the Interdendritic B2 Phase Phase

August 15, 2010
Author(s)
Leonid A. Bendersky, Ke Wang, William J. Boettinger, Dale E. Newbury, K. Young, B. Chao
Multi-component Zr-Ti-Ni-TM (TM=V, Cr, Mn and Co) cast alloys intended for use as negative electrodes in Ni metal hydride batteries were studied to determine the solidification microstructure and solidification path in the Part I of this paper. Part II of

Solidification of a heterogeneous Multiphase Laves-based Hydrogen Storage Alloy

August 15, 2010
Author(s)
William J. Boettinger, Dale E. Newbury, Ke Wang, Leonid A. Bendersky, Chun Chiu, Ursula R. Kattner, K. Young, B. Chao
The solidification microstructure of a nine-element Zr-Ni based AB(sub 2) type C14/C15 Laves hydrogen storage alloy is determined. The selected composition represents a class of alloys being examined for usage as a metal hydride electrode in nickel metal

Modeling Reactive Wetting when Inertial Effects are Dominant

June 30, 2010
Author(s)
Daniel Wheeler, James A. Warren, William J. Boettinger
Recent experimental studies of molten metal droplets wetting and spreading on high temperature reactive substrates have established that the majority of triple-line motion occurs when inertial effects are dominant. In light of these studies, this paper

Thermodynamic model of hydride formation and dissolution in spherical particles

June 30, 2010
Author(s)
Yuri Mishin, William J. Boettinger
A model of hydride formation and dissolution has been proposed for a single spherical nano-particle and for a colletion of such particles with a given size distribution. The phase transformation strain gives rise to an elastic barrier of the transformation

A Multicomponent and Multiphase Model of Reactive Wetting

June 4, 2010
Author(s)
Walter Villanueva, William J. Boettinger, Geoffrey B. McFadden, James A. Warren
A diffuse-interface model of reactive wetting with intermetallic formation is presented. The model incorporates fluid flow, solute diffusion, and phase change that are based on the total molar Gibbs energy of a ternary system with four phases. Numerical

Atomistic simulation of hillock growth

May 15, 2010
Author(s)
Timofey Frolov, William J. Boettinger, Yuri Mishin
The goal of this paper is to explore mechanisms of hillock and whisker growth in stressed poly-crystalline films by molecular dynamics simulations. Our stress-free model consists of three grains and a triple line aligned perpendicular to a free surface

Diffusion Parameters and Growth Mechanism of Phases in the Cu-Sn System

April 15, 2010
Author(s)
William J. Boettinger, C Ghosh, A Paul
The tracer diffusion coefficients of the elements as well as the integrated interdiffusion coefficients are measured for the Cu(sub3)Sn and Cu(sub6)Sn(Sub5) intermetallic compounds using incremental diffusion couples. The activation energies are determined

Whisker Formation in Pb-Free Surface Finishes

February 2, 2010
Author(s)
Gery R. Stafford, Maureen E. Williams, Jae W. Shin, Kil-Won Moon, William J. Boettinger, Carlos R. Beauchamp
Tin(Sn)-lead(Pb) alloys have been used extensively for surface finishing of electronic components in part because Pb was found to be effective in retarding Sn whisker growth in electrodeposits. Altough whiskers appear to be a local response to the

Bending of a Bimetallic Beam due to the Kirkendall Effect

January 1, 2010
Author(s)
William J. Boettinger, Geoffrey B. McFadden
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, the bending being due to the creation and /annihilation of vacancies necessitated by unequal

Examination of Sn Electrodeposit on a Substrate Not Forming Intermetallic

October 16, 2008
Author(s)
Maureen E. Williams, Kil-Won Moon, William J. Boettinger, Daniel Josell
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 and cause the growth of Sn whiskers. To