A summar y of the final progress achieved in two Metals Affordability Initiative (MAI) programs (RR-12 and RR-13) that were funded by the US Air Force to develop the necessary integrated computational materials engineering (ICME)... more
A summar y of the final progress achieved in two Metals Affordability Initiative (MAI) programs (RR-12 and RR-13) that were funded by the US Air Force to develop the necessary integrated computational materials engineering (ICME) framework, knowledge, and supporting database to model and predict location-specific fatigue properties across the entire titanium supply chain is presented. Validation of this ICME framework which allows for the prediction of location specific low cycle fatigue (LCF) and high cycle fatigue (HCF) behavior on complex production components in electro-polished and shot peened surface conditions will be presented. In addition, validation of a new shot peening capability embedded with the commercial software package DEFORM™ will be presented.
... SL SEMIATIN, Senior Scientist, is with the Air Force Research Laboratory, Materials and Manufacturing Directorate, AFRL/MLLM. Contact e-mail: ayman.salem@fnnet.wpafbml.org Manuscript submitted May 15, 2004. Page 2. 260VOLUME 37A,... more
... SL SEMIATIN, Senior Scientist, is with the Air Force Research Laboratory, Materials and Manufacturing Directorate, AFRL/MLLM. Contact e-mail: ayman.salem@fnnet.wpafbml.org Manuscript submitted May 15, 2004. Page 2. 260VOLUME 37A, JANUARY 2006 ...
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... SL SEMIATIN, Senior Scientist, is with the Air Force Research Laboratory, Materials and Manufacturing Directorate, AFRL/MLLM. Contact e-mail: ayman.salem@fnnet.wpafbml.org Manuscript submitted May 15, 2004. Page 2. 260VOLUME 37A,... more
... SL SEMIATIN, Senior Scientist, is with the Air Force Research Laboratory, Materials and Manufacturing Directorate, AFRL/MLLM. Contact e-mail: ayman.salem@fnnet.wpafbml.org Manuscript submitted May 15, 2004. Page 2. 260VOLUME 37A, JANUARY 2006 ...
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The impacts of microstructure and texture on the ingress of oxygen were studied with Ti-6242S and Ti-64. Titanium samples were solutionized and heated to produce equiaxed and colony microstructures, followed by oxidation tests in air.... more
The impacts of microstructure and texture on the ingress of oxygen were studied with Ti-6242S and Ti-64. Titanium samples were solutionized and heated to produce equiaxed and colony microstructures, followed by oxidation tests in air. Oxygen ingress was measured using etched optical images, EMPA, and SEI techniques as functions of c and a alpha lath orientations. In addition, hardness measurements at different depths, corresponding to alpha orientations, were obtained and compared to estimate mechanical properties. Results, including identification of phases that formed during oxidation, will be presented for both alloys and both microstructure conditions.
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... While α-alloys are rich in α-stabilizers (eg, Al, O, N, and C), ß-alloys are rich in AA Salem ( ) Wright Patterson Air Force Base, 2210 Tenth St. Building 655 Room 053, WPAFB, OH 45433, USA e-mail: ayman.salem@wpafb.af.mil... more
... While α-alloys are rich in α-stabilizers (eg, Al, O, N, and C), ß-alloys are rich in AA Salem ( ) Wright Patterson Air Force Base, 2210 Tenth St. Building 655 Room 053, WPAFB, OH 45433, USA e-mail: ayman.salem@wpafb.af.mil ß-stabilizers (eg, V, Mo, Nb, Cr, Fe, and Si). ...
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Page 1. A COMPARISON OF DEFORMATION TEXTURES AND MECHANICAL PROPERTIES PREDICTED BY DIFFERENT CRYSTAL PLASTICITY CODES Craig S. Hartley El Arroyo Enterprises LLC Sedona, AZ USA Paul ...
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Burgers vector populations, dislocation types and dislocation densities are determined within individual grains of a polycrystalline commercial-purity titanium specimen by extending prior method of differentiating individual grains in a... more
Burgers vector populations, dislocation types and dislocation densities are determined within individual grains of a polycrystalline commercial-purity titanium specimen by extending prior method of differentiating individual grains in a polycrystalline sample. The ...
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Page 1. Modeling Anisotropic Stress-Strain Response and Crystallographic Texture Evolution in a-Titanium during Large Plastic Deformation using Taylor-Type Models: Influence of Initial Texture and Purity XIANPING WU, SURYA ...
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ABSTRACT Oxygen ingress is critical to the high-temperature behavior of alpha + beta titanium alloys. The current study investigated the impact of crystallographic orientation on the ingress of oxygen in Ti-6Al-2Sn-4Zr-2Mo+Si, for colony... more
ABSTRACT Oxygen ingress is critical to the high-temperature behavior of alpha + beta titanium alloys. The current study investigated the impact of crystallographic orientation on the ingress of oxygen in Ti-6Al-2Sn-4Zr-2Mo+Si, for colony microstructures. The oxygen ingress depth was estimated using EDS, EPMA, microhardenss, and optical microscopy. Results indicate that the depth of oxygen ingress in colony microstructures is dependent on α-laths’ orientation relative to the ingress direction. A finite element model was developed to simulate the oxygen ingress in three different lath orientations. Results were used to calibrate the effective diffusivity for the colony microstructure. The relationships between the lath orientations, hardness, and ingress depth were discussed.
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The evolution of microstructure in commercial-purity titanium during cold rolling to a thickness strain of 2.6 was quantified using electron backscatter diffraction. The measurements were analyzed in terms of the mean grain size and the... more
The evolution of microstructure in commercial-purity titanium during cold rolling to a thickness strain of 2.6 was quantified using electron backscatter diffraction. The measurements were analyzed in terms of the mean grain size and the density of boundaries (the ratio of total boundary length to the scanned area). The density of high-angle boundaries as a function of thickness strain had
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Research Interests: Materials Engineering, Mechanical Engineering, Microstructure, Plasticity, Anisotropy, and 15 moreFlow, Cross sections, High Temperature, Deformation Mechanisms, Phase, Cross Section, Microstructures, Plastic deformation, Deformation Mechanism, Critical Resolved Shear Stress, Anisotropia, Large Strain, Flow Stress, Interphase, and Compression test
High-resolution X-ray diffraction (XRD) line-profile analysis was used to characterize slip activity and twinning in commercial-purity titanium (CP-Ti) during hot rolling. The effect of {10.1} and {10.2} twins on XRD patterns was deduced... more
High-resolution X-ray diffraction (XRD) line-profile analysis was used to characterize slip activity and twinning in commercial-purity titanium (CP-Ti) during hot rolling. The effect of {10.1} and {10.2} twins on XRD patterns was deduced using the DIFFAX software. The density of twin boundaries was then incorporated into the XRD pattern-fitting procedure for evaluating dislocation densities, slip activity, and subgrain size. It
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Page 1. JOM April 2011 34 www.tms.org/jom.html How would you
describe the overall significance of this paper? This paper presents a novel ap-proach for quantifying the micro-structure and building searchable databases. ...
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Research Interests: Materials Engineering, Mechanical Engineering, Microstructure, Strain Rate, Crystal Plasticity, and 15 moreOptical microscopy, Deformation, Plastic, Dislocations, Room Temperature, Plastic deformation, Numerical computation, Experimental Measurement, Compressive Stress, Shear Modulus, Deformation Mechanism, Strain Hardening, Stacking Fault Energy, Microstructure evolution, and Compression test
A new Taylor-type polycrystalline model has been developed to simulate the evolution of crystallographic texture and the anisotropic stress–strain response during large plastic deformation of high purity α-titanium at room temperature.... more
A new Taylor-type polycrystalline model has been developed to simulate the evolution of crystallographic texture and the anisotropic stress–strain response during large plastic deformation of high purity α-titanium at room temperature. Crystallographic slip, deformation twinning and slip inside twinned regions were all considered as contributing mechanisms for the plastic strain in the model. This was accomplished by treating the dominant
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... induced strain hardening of high-purity α-titanium at room temperature were incorporated into constitutive laws to describe the evolution of both twin and slip resistance due to deformationtwinning. The proposed equations were... more
... induced strain hardening of high-purity α-titanium at room temperature were incorporated into constitutive laws to describe the evolution of both twin and slip resistance due to deformationtwinning. The proposed equations were incorporated in a Taylor-type crystal plasticity ...
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ABSTRACT Microstructure evolution in commercial-purity titanium during plane-strain multipass rolling to a true thickness strain of 2.66 at 77 and 293 K was quantified. Deformation at both temperatures was accompanied by twinning. At 77... more
ABSTRACT Microstructure evolution in commercial-purity titanium during plane-strain multipass rolling to a true thickness strain of 2.66 at 77 and 293 K was quantified. Deformation at both temperatures was accompanied by twinning. At 77 K, twinning was more extensive in terms of the fraction of twinned grains and the duration of the twinning stage. Rolling to a true thickness strain of 2.66 resulted in the formation of a microstructure with a grain/subgrain size of ∼80 nm at 77 K or ∼200 nm at 293 K. The contribution of various mechanisms to the strength of titanium following rolling at 77 and 293 K was analyzed quantitatively.