30 Result(s)

Chapter and Conference Paper

Determining the nanoscale chemistry and behavior of interfaces and phases in Al-Si(-Cu-Mg) nanoparticles using in-situ TEM

Understanding fundamental phenomena such as the structure and composition of the solid-liquid interface, the partitioning of elements between the solid and liquid phases during crystal growth, and critical fac...

J. M. Howe, S. K. Eswaramoorthy… in EMC 2008 14th European Microscopy Congress… (2008)

Article

The effect of interfacial energy and phase fraction on the particle shape and the dihedral angles in two-phase small particles containing a cusp-oriented interface; computational model

The equilibrium shape and dihedral angles at the solid–liquid–vapor tri-junctions of two-phase alloy small particles containing a cusp-oriented interface were modeled as a function of phase fraction, surface e...

A. M. Mebed, J. M. Howe in Journal of Materials Science (2007)

Article

Atomic structure of a {110} Zr/ZrN interface

Investigation of the atomic structure of a micrometer-level faceted (011) Zr/ZrN interface by high-resolution transmission electron microscopy (HRTEM), diffraction contrast imaging, and near-coincidence-site (...

P. Li, J. M. Howe, W. T. Reynolds Jr. in Metallurgical and Materials Transactions A (2006)

Article

Non-aggregated Pd nanoparticles deposited onto catalytic supports

Nanostructured powders have shown great promise for a variety of applications including chemical gas sensors, high surface area supports for catalysis, tribology, chemical mechanical polishing, and optoelectro...

C.E. Allmond, V.P. Oleshko, J.M. Howe, J.M. Fitz-Gerald in Applied Physics A (2006)

Article

Investigation of the structure and composition of a {111} incoherent Zr/ZrN interface containing ledges by high-resolution transmission electron microscopy, image simulation, electron energy-loss spectroscopy, energy-filtering transmission electron microscopy, and near-coincidence-site analysis

Investigation of the atomic structure of a (111) Zr/ZrN interface shows that it is a type-3 incoherent interface (i.e., high-index orientation relationship with a low-index interface plane in only one phase), as ...

P. Li, J. M. Howe, W. T. Reynolds Jr. in Metallurgical and Materials Transactions A (2006)

Article

In-Situ TEM Studies of Sessile Dislocation Arrangements and N Vacancy Ordering in ZrN

Dissociation of perfect 1/2<110> single dislocations into two 1/6<112> Shockley partial dislocations in ZrN was observed by transmission electron microscopy (TEM). The 1/2<110> single dislocations have a super...

P. Li, J. M. Howe in MRS Online Proceedings Library (2004)

Article

On the solute field and composition of γ plates in an Al-22 at. pct Ag alloy

K. T. Moore, J. M. Howe, D. R. Veblen in Metallurgical and Materials Transactions A (2002)

Article

Discussion of “Surface relief and the displactive transformation to the lamellar microstructure in TiAl” and “Nanometer-scale, fully lamellar microstructure in an aged TiAl-based alloy”

J. F. Nie, J. M. Howe, V. K. Vasudevan… in Metallurgical and Materials Transactions A (2000)

Chapter

Characterization of Heterophase Transformation Interfaces by High-Resolution Transmission Electron Microscope Techniques

This paper describes the application of several high-resolution transmission electron microscope (HRTEM) techniques to determine the structure, composition and dynamics of heterophase transformation interfaces...

J. M. Howe in Impact of Electron and Scanning Probe Microscopy on Materials Research (1999)

Article

Microstructural evaluation of Ti-6-22-22 alloy

In this study, the microstructure of Ti-6-22-22 alloy as a function of aging time and temperature was examined and related to its fracture behavior. Fracture primarily occurred along prior β grain boundaries, but...

A. W. Wilson, J. M. Howe in Metallurgical and Materials Transactions A (1998)

Article

Diffusion fields associated with size and shape coarsening of oblate spheroids

The diffusion field or solute concentration distributed around an oblate spheroidal particle simulating a disc-shaped precipitate has been solved for varying particle aspect ratios and varying concentrations a...

Yiwen Mou, J. M. Howe in Metallurgical and Materials Transactions A (1997)

Article

High-resolution transmission electron microscopy investigation of the face-centered cubic/hexagonal close-packed martensite transformation in Co-31.8 wt pct Ni alloy: Part 1. Plate interfaces and growth ledges

The face-centered cubic/hexagonal close-packed (fcc/hcp) martensite transformation in a Co-31.8 wt pct Ni alloy was studied by high-resolution transmission electron microscopy (HRTEM). High-resolution transmis...

D. W. Bray, J. M. Howe in Metallurgical and Materials Transactions A (1996)

Article

High-resolution transmission electron microscopy investigation of the face-centered cubic/hexagonal close-packed martensite transformation in Co-31.8 wt pct Ni alloy: Part 2. Plate intersections, extended defects, and nucleation mechanisms

The face-centered cubic/hexagonal close-packed (fcc/hcp) martensite phase transformation in a Co-31.8 wt pct Ni alloy was studied by high-resolution transmission electron microscopy (HRTEM). The HRTEM was used...

D. W. Bray, J. M. Howe in Metallurgical and Materials Transactions A (1996)

Article

A high-resolution transmission electron microscopy study of interfaces between the γ, B2, and α₂ phases in a Ti-Al-Mo alloy

Conventional and high-resolution transmission electron microscopy (HRTEM) were used to examine the interfacial structures in a Ti-50Al-5Mo (at. pct) alloy which was processed to produce combinations of γ, B2, ...

S. Das, J. M. Howe, J. H. Perepezko in Metallurgical and Materials Transactions A (1996)

Article

Determination of the atomic structure, mechanisms and kinetics of precipitate growth in solids by in situ hot-stage high-resolution transmission electron microscopy

In situ hot-stage high-resolution transmission electron microscopy (HRTEM) provides unique capabilities for determining the mechanisms and kinetics of interface motion in solids at the atomic level. Such informa...

J. M. Howe, W. E. Benson in Interface Science (1995)

Article

Lengthening kinetics of \((01\bar 10)\) γ-TiH precipitates in α-Ti in the temperature range of 25 °c to 80 °c

Formation of y hydrides in α titanium involves a hcp → fct lattice transformation with hydrogen as an interstitial diffusing species. Since the crystallography of this reaction resembles that of a martensitic ...

M. M. Tsai, J. M. Howe in Metallurgical and Materials Transactions A (1995)

Article

Grain-boundary precipitation and fracture behavior of an Al-Cu-Li-Mg-Ag alloy

Yiwen Mou, J. M. Howe, E. A. Starke in Metallurgical and Materials Transactions A (1995)

Article

Characterization of a diffusion-bonded Al-Mg alloy/SiC interface by high resolution and analytical electron microscopy

The interfacial structure of a diffusion-bonded Al-4.55 at. pct Mg/SiC interface was examined by conventional and high-resolution transmission electron microscopy. Formation of Mg₂Si, MgO, and Al₂MgO₄ was observe...

P. L. Ratnaparkhi, J. M. Howe in Metallurgical and Materials Transactions A (1994)

Article

Composition and stability of Ω phase in an Al-Cu-Mg-Ag Alloy

Transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS) were employed to determine the stability and composition of the Ω phase in an Al-Cu-Mg-Ag alloy. It is shown that the Ω. ph...

Y. C. Chang, J. M. Howe in Metallurgical Transactions A (1993)

Article

The effect of ternary trace additions on the nucleation and growth of γ′ precipitates in an Al-4.2 At. Pct Ag alloy

The role of trace elements on the nucleation and growth kinetics of γ′ precipitates in an aged Al-4.2 at. pct Ag alloy was determined. Comparing the characteristic properties of different trace elements on the...

N. Prabhu, J. M. Howe in Metallurgical Transactions A (1992)