Hydrogen Induced Delayed Failure of High Strength Alloy Steel Wires (2006)
Langstaff, D. C., Meyrick, G., Hirth, J. P.
Pub. in Corrosion, v37 n8 p429-437 Aug 1981.
THE DIFFUSIONAL CONTRIBUTION TO THE KNUDSEN CELL EFFUSION FLUX (2005)
I T I RECOGNIZED THAT THE GEOMETRY OF A Knudsen vapor effusion cell influences the kinetics of the molecular effusion of the vapor from within the cell. Clausing, Whit an and Motzfeldt have given...
ON THE NUCLEATION RATE OF VACANCY CLUSTERS IN CRYSTALS. (2005)
Homogeneous nucleation theory is applied to the process of vacancy condensation in crystals. The results show that homogeneous nucleation cannot account for the observed densities of vacancy clusters...
THE KINETICS OF DIFFUSION CONTROLLED WHISKER GROWTH, (2005)
The problem of surface diffusion controlled whisker is considered in a moving frame of reference. In addition, diffusive exchange with the substrate, a problem not treated heretofore, is considered....
The Sublimation of Basal Surfaces of Zinc Oxide. (2002)
McVicker,J. E., Rapp,R. A., Hirth,J. P.
Basal surfaces of both undoped and lithium-doped single crystals of zinc oxide were sublimated under Langmuir free vaporization conditions and under various partial pressures of oxygen. The...
Plastic Instability in Uniaxial Tension Tests, (2002)
Prepared in cooperation with Ohio State Univ., Columbus. Dept. of Metallurgical Engineering and Cornell Univ., Ithaca, NY Dept. of Materials Science and Engineering.
Tensile and Shear Fracture of an HSLA Steel, (2002)
Schroth,J. G., Hoagland,R. G., Hirth,J. P., Rosenfield,A. R.
The purpose of this investigation was to characterize the mixed mode I - mode III fracture resistance of an HSLA steel, similar to ASTM A710 Grade A, of composition 0.04% C, 0.04% Nb, 1.17% Cu, 0.90%...
Rosenfield,A. R., Hirth,J. P., Schroth,J. G.
The report discusses effects of composition and heat treatment on the fracture behavior of a group of steels based on ASTM A712A. Very low transition temperatures were observed in a number of cases....
Internal Oxidation of Ag-In Alloys: Stress Relief and the Influence of Imposed Strain, (2002)
Guruswamy,S., Park,S. M., Hirth,J. P., Rapp,R. A.
The kinetics of internal oxidation of silver-indium alloys containing 3.5, 5.9, and 9.8 at. % In in air at temperatures 773 to 973 K were established by TGA with no load applied to the specimens....
THERMAL ETCH PITS AND DISLOCATIONS IN SILVER (1998)
WINTERBOTTOM,W.L., ROBINSON,W.H., HIRTH,J.P.
Silver single crystals having (100), (110) and (111) orientations were heated to 750 C in a vacuum of about 1/100,000 to 10 to the -6th power mm of Hg. The density of the thermal etch pits which...
THE ANGULAR DISTRIBUTION OF VAPOR FLOWING FROM A KNUDSEN CELL (1998)
Equations for the spatial distribution and total effusion flow of molecules effusing from a Knudsen orifice by both surface diffusion and vapor transport are developed. The equations are exact,...
THE VAPORIZATION KINETICS OF SOLID SILVER (1998)
The rates of free vaporization of single crystals of silver were measured as a function of the crystallographic orientation of the vaporizing surface, the mode of surface preparation, the degree of...
ON DISLOCATION ENERGIES AND THE CONCEPT OF LINE TENSION. (1998)
Hirth, J. P., Jossang, T., Lothe, J.
The concept of a dislocation line tension is discussed and explicit expressions for the total energy of various dislocation configurations in different orientations are given. Based on these energy...
AN INVESTIGATION OF INTERDIFFUSION IN METALLIC SINGLE CRYSTALS. (1998)
With the objective of studying defect interaction in the diffusion zone of binary couples, three independent investigations were carried on this project. They are: (1) determination of the...
ON THE CONTACT ANGLE IN HETEROGENEOUS NUCLEATION UPON A SUBSTRATE, (1998)
The dependence of the nucleation rate equation on the contact angle parameter theta is analyzed for heterogeneous nucleation from vapor or from liquid. It is shown that externally imposed constraints...
Epitaxial Deposition of Silver on Molybdenite. (1998)
Silver was found to deposit epitaxially on molybdenite at substrate temperatures from -165C to 625C. The degree of epitaxy decreased with decreasing substate temperature with rotations of up to 4...
An Atomistic Approach to Deformation and Fracture of Materials. (1998)
Hoagland,R. G., Gehlen,P. C., Hirth,J. P.
This report summarizes research concerning a critical test of atomic-scale computer simulation applied to the mechanical properties of materials. Because of certain advantages of the interatomic...
The Interaction between Line Force Arrays and Planar Cracks. (1998)
Hirth,J. P., Hoagland,R. G., Gehlen,P. C.
The utility of line force fields in computer simulations of lattice defects is discussed. These fields are shown to provide a facile method for introducing realistic flexible boundary conditions on...
Cohen,M., Hirth,J. P., Jacobson,L., Mehrabian,R.
A three-day conference on Rapid Solidification Technology was held on 7-9 July as a portion of the 1981 MRC meeting. The program and attendees are appended as Section V of this report. The results of...
Effect of UV Illumination on the Sublimation of Basal Surfaces of Zinc Oxide. (1998)
Carey,D. A., Rapp,R. A., Hirth,J. P.
Despite substantial agreement in the measured kinetics for the sublimation of basal surfaces of zinc oxide crystals, differing mechanisms have been proposed. To help resolve the questions, the effect...
Research on the Kinetics of Phase Changes in Solids. (1998)
A brief outline is presented of experimental observations and theoretical interpretations of hydrogen embrittlement of steels. Detailed results on the effect of precharged hydrogen on reduction in...
Ideal Fracture-Resistant Microstructures. (1998)
Rosenfield, A. R., Hirth, J. P., Manoharan, M., Raghavachary, S.
The main objective of this grant is to quantify the concept of ideal microstructures for fracture resistance. To approach this goal, a variety of steels and heat treatments was investigated. Of...
Mixed Mode I/III Fracture Toughnesss of an Experimental Rotor Steel. (1998)
Raghavachary, S., Rosenfield, A. R., Hirth, J. P.
Mixed mode I/III toughness tests were performed on a Ni-Cr-Mo-V rotor steel that exhibited very high mode I toughness; minimum toughness occurred under mixed mode loading conditions; influence of...
Effects of Hydrogen on the Mixed Mode I/III Toughness of a High-Purity Rotor Steel. (1998)
J integral tests, both pure mode I and mixed mode I/III in character, were performed on a high-purity Ni-Cr-Mo-V rotor steel; the steel was tested in the uncharged condition and after gaseous...
Dislocation Structures in Be12Nb After High-Temperature Deformation. (1998)
Bruemmer, S. M., Charlot, L. A., Brimhall, J. L, Hirth, J. P.
Dislocation structures and faults in vacuum-hot-pressed Be12Nb have been examined after compressive deformation at 1200 deg.C; both perfect and partial dislocations were observed in the deformed...
Twinning Relationship in Be12Nb. (1998)
Charlot, L. A., Brimhall, J. L., Thomas, L. E., Bruemmer, S. M., Hirth, J. P.
Annealing twins and extended and short-range faults were examined in Be12Nb processed by vacuum-hot-pressing and HIP. Short-range faults showed a (001) habit plane, whereas twins and extended faults...
Properties and Potential of High-Temperature Niobium Beryllides. (1998)
Bruemmer, S. M., Brimhall, J. L., Hirth, J. P.
Recent research on the low- and high-temperature properties of two beryllium-niobium intermetallic compounds, Be12Nb and Be17Nb2, is reviewed and discussed; strength (bend and compression), hardness...
Strength and Toughness of Beryllium-Niobium Intermetallic Compounds. (1998)
Bend and compression strengths, fracture toughness, and high-temperature microhardness of Be-Nb intermetallic compounds were measured at temperatures up to 1200 C; Be12Nb and Be17Nb2 materials...
Hot-Hardness Comparisons Among Isostructural Be12X Intermetallic Compounds. (1998)
Bruemmer, S. M., Arey, B. W., Brimhall, J. L., Hirth, J. P.
Hot hardness has been measured in seven isostructural Be12X compounds: Be12Cr, Be12Mn, Be12V, Be12Mo, Be12Ti, Be12Ta, and Be12Nb. All vacuum-hot-pressed (VHP) materials exhibited similar hardness...
A Mixed Mode I/III Fracture Toughness Correlation. (1998)
This paper discusses the correlation which relates the mixed-mode fracture toughness to the process zone size. Several materials, including aluminum alloy 2034 are considered.
Mixed Mode I/III Fracture Toughness of 2034 Aluminum Alloys. (1998)
Feng, Xiaoxin, Kumar, A. M., Hirth, J. P.
A study of the mixed mode i and iii fracture resistance of four 2034 aluminum alloys with varying manganese content is presented in this paper. the mixed mode fracture tests are carried out using...
In Situ Synthesis of a MoSi2/SiC Composite Using Solid State Displacement Reactions. (1998)
Brimhall, J. L., Vetrano, J. S., Hirth, J. P.
A high-strength in-situ composite of mosi2/sic was synthesized using a solid state displacement reaction between mo2c and si by blending mo2c and si powders and vacuum hot-pressing the powders at...
Fracture of Alumina Particulate Reinforced Aluminium Alloy Matrix Composites. (1998)
The fracture mechanisms operative in al-alloy matrices (2014-0 and 2024-0) reinforced with alumina particulates were investigated. it was determined how volume fraction, particulate size and...
During a solid state reaction, solid state displacement reactions can produce in situ intermetallic matrix composites in a process where an intermetallic phase and a potential reinforcing phase are...
This paper concerned mmc in some important way and contained information about, utilized, or discussed these subjects: basic topics:, dr mmc, mmc, review materials and material types:, (al2o3)p/6061,...
Plastic Deformation in Al-Alloy Matrix-Alumina Particulate Composites. (1998)
Kamat, S. V., Rollett, A. D., Hirth, J. P.
This paper concerned mmc in some important way and contained information about, utilized, or discussed these subjects: basic topics:, dr mmc, mmc materials and material types:, (al2o3)p/2014,...
Pestes, R. H., Kamat, S. V., Hirth, J. P.
Active research has led to considerable advances in an understanding of particulate reinforced mmcs. in particular, substantial experimental and theoretical work 1-20 has been done on the effect of...
Synthesis of a MoSi2-SiC Composite In Situ Using a Solid State Displacement Reaction. (1998)
A high strength in-situ composite of mosi2-sic was synthesized using a solid state displacement reaction between mo2c and silicon. diffusion couples between mo2c and silicon processed at 1200 degrees...
Fracture Toughness of Al-4 Percent Mg/Al2O3p Composites. (1998)
Pestes, R. H., Kamat, S. V., Hirth, J. P.
Fracture toughness tests were carried out on al-4%mg/al2o3(sub p) composites containing different sizes and volume fractions of alumina particulates. the results indicated that the fracture toughness...
Kamat, S. V., Hirth, J. P., Mehrabian, R.
This paper concerned mmc in some important way and contained information about, utilized, or discussed these subjects: basic topics:, data, dr mmc, mmc, mmc data materials and material types:,...
Synthesis of Composites In Situ Using Displacement Reactions. (1998)
Solid state displacement reactions are being studied at Pacific Northwest Laboratory as a method of synthesizing intermetallic and ceramic composites in situ. A nanometer-scale interwoven composite...
Solid state displacement reactions are being evaluated as a technique to produce intermetallic/ceramic matrix composites in situ. Solid state displacement reactions are diffusional phase...
In Situ Synthesis of a MoSi2/SiC Composite Using Solid State Displacement Reactions. (1998)
Brimhall, J. L., Vetrano, J. S., Hirth, J. P.
A high strength in situ composite of MoSi2/SiC was synthesized using a solid state displacement reaction between Mo2C and Si by blending Mo2C and Si powders and vacuum hot pressing the powders at...
Deformation of Nanoscale Cermets. (1998)
Cobalt-tungsten carbide cermets are protypical dual-phase composites wherein the metal is the minor phase (volume fraction, f(sub m) =0.1-0.2), but is continuous, because of capillarity effects at...
Synthesis of a MoSi2/SiC Composite In Situ Using a Solid State Displacement Reaction. (1998)
Solid state displacement reactions are being studied at Pacific Northwest Laboratory (PNL) as a method of synthesizing intermetallic and ceramic composites in situ. A high-strength in situ composite...
MECHANICAL PROPERTIES OF PARTICULATE-REINFORCED ALUMINUM-MATRIX COMPOSITES. (1998)
Kamat, S. V., Hirth, J. P., Mehrabian, R.
Pergamon Press Ltd. : Great Britain
Anisotropic elastic fields of twist boundaries (1992)
Relations for linear anisotropic elastic fields of parallel arrays of dislocations are developed. These fields are used to compute the displacement fields of twist boundaries composed of a square...
Elastic analysis of the energy and relaxation of stepped surfaces (1991)
Srolovitz, David J., Hirth, J. P.
We present an analytical, elastic analysis for the energy and relaxation of stepped surfaces. The analysis is based upon the observation that the most prominent feature of the non-reconstructive...
Image forces on screw dislocations in multilayer structures (1987)
Kamat, S. V., Hirth, J. P., Carnahan, Brice
Peer Reviewed
Hydrogen adsorption at dislocations and cracks in Fe (1978)
Solute adsorption to dislocations and cracks is considered in both the Boltzmann and Fermi-Dirac models. Explicit sums are developed for the integral amount of solute adsorbed in the defect fields....
Stringfellow, Gerald B., Hirth, J.P.
A model is presented for growth by so-called composition pulling, wherein an epitaxial deposit grows coherently but with a composition different from that which would be in bulk equilibrium with the...
Flow equations for graphite (1976)
Hirth, J. P., Hucke, Edward E., Coble, R. L.
In analyzing erosion of graphite at high strain rate (~107 sec-1) and temperature (~4000[deg]C), it is necessary to have some approximation for the constitutive equation. Data for graphite from...