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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 361 records · Page 20
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Growth of titania and tin oxide from Ti 2 SnC via rapid thermal oxidation in air for lithium-ion battery application

Herein, we report the synthesis of TiO 2 –SnO 2 –C/carbide hybrid electrode materials for Li-ion batteries (LIBs) via two different methods of controlled oxidation of layered Ti 2 SnC. The material was partially oxidized in an open-air furnace (OAF) or using a rapid thermal annealing (RTA) approach to obtain the desired TiO 2 –SnO 2 –C/carbide hybrid material; the carbide phase encompassed both residual Ti 2 SnC and TiC as a reaction product. We tested the oxidized materials as an anode in a half cell to investigate their electrochemical performance in LIBs. Analysis of the various oxidation conditions indicated the highest initial lithiation capacity of 838 mAh/g at 100 mA/g for the sample oxidized in the OAF at 700°C for 1 h. Still, the delithiation capacity dropped to 427 mAh/g and faded over cycling. Long-term cycling demonstrated that the RTA sample treated at 800°C for 30 s was the most efficient, as it demonstrated a reversible capacity of around 270 mAh/g after 150 cycles, as well as a specific capacity of about 150 mAh/g under high cycling rate (2000 mA/g). Given the materials’ promising performance, this processing method could likely be applied to many other members of the MAX family, with a wide range of energy storage applications.

25 ENERGY STORAGE↗
DOE OSTI2024

Selective laser sintering and spark plasma sintering of (Zr,Nb,Ta,Ti,W)C compositionally complex carbide ceramics

Abstract Two advanced manufacturing processes, spark plasma sintering (SPS) and selective laser sintering (SLS), have been developed for synthesis of (Zr,Nb,Ta,Ti,W)C compositionally complex carbide (CCC) via reactive sintering of a powder mixture of constitute monocarbides. X‐ray diffraction analysis confirmed that the single‐phase CCC can be formed by both SPS and SLS. While a homogenous microstructure with uniform metal element distributions was developed during SPS, three‐layer microstructures with a thin TiC‐rich layer and two TaC‐rich layers along with a TiO 2 ‐rich surface layer containing W nanoparticles were formed during SLS. In addition, cellular structures with W, Zr, and Ti element segregation and dislocations on cell boundaries were observed in the SLS‐CCC sample, indicating the effect of nonequilibrium conditions on microstructure formation during laser melting followed by rapid cooling and solidification process. Compared to the SPS‐CCC sample, the SLS‐CCC showed enhanced hardness and reduced thermal conductivity, which may be related to their unique cellular structures.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Demonstration of a side-pumped cross-seeded thin-slab pre-amplifier for high-power Ti:Sa laser systems

Here, we demonstrate a room-temperature Ti:Sapphire (Ti:Sa) amplifier that uses a cross pump-seed geometry (cross-thin-slab) to generate 30-mJ output pulses at 0.5-kHz repetition rate, and 25 mJ at 1 kHz when pumped by 100-mJ, 515-nm pulses from a diode-pumped Yb:YAG laser. The geometry allows to maintain a crystal temperature of ~30°C using cooling water at 10°C. The amplifier is an attractive solution for use in the first stages of amplification in high peak and high average power chirped pulse amplification laser systems.

47 OTHER INSTRUMENTATION↗
DOE OSTI2021

A Constitutive Structural Parameter for the Work Hardening Behavior of Additively Manufactured Ti-6Al-4V

The mechanical behavior of Ti-6Al-4V produced by additive manufacturing processes is assessed based on a formulation developed from the Kocks-Mecking relationship. A constitutive parameter derived for the microstructure is characteristic of the work hardening behavior determined by the plastic strain between the proportional limit and the strength at the instability point. The varied plasticity behavior associated with surface and build direction effects can be evaluated with this approach as presented for the case of Ti-6Al-4V under uniaxial tension.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Synthesis of Nano-Oxide Precipitates by Implantation of Ti, Y and O Ions in Fe-10%Cr: Towards an Understanding of Precipitation in Oxide Dispersion-Strengthened (ODS) Steels

The properties of oxide dispersion-strengthened steels are highly dependent on the nature and size distribution of their constituting nano-oxide precipitates. A fine control of the processes of synthesis would enable the optimization of pertinent properties for use in various energy systems. This control, however, requires knowledge of the precise mechanisms of nucleation and growth of the nanoprecipitates, which are still a matter of debate. In the present study, nano-oxide precipitates were produced via the implantation of Y, Ti, and O ions in two different sequential orders in an Fe-10%Cr matrix that was subsequently thermally annealed. The results show that the oxides that precipitate are not necessarily favoured thermodynamically, but rather result from complex kinetics aspects related to the interaction between the implanted elements and induced defects. When Y is implanted first, the formation of nanoprecipitates with characteristics similar to those in conventionally produced ODS steels, especially with a core/shell structure, is evidenced. In contrast, when implantation starts with Ti, the precipitation of yttria during subsequent high-temperature annealing is totally suppressed, and corundum Cr 2 O 3 precipitates instead. Moreover, the systematic involvement of {110} matrix planes in orientation relationships with the precipitates, independently of the precipitate nature, suggests matrix restriction effects on the early stages of precipitation.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Mechanical Behavior Assessment of Ti-6Al-4V ELI Alloy Produced by Laser Powder Bed Fusion

The present work correlates the quasi-static, tensile mechanical properties of additively manufactured Ti-6Al-4V extra low interstitial (ELI, Grade 23) alloy to the phase constituents, microstructure, and fracture surface characteristics that changed with post-heat treatment of stress relief (670 °C for 5 h) and hot isostatic pressing (HIP with 100 MPa at 920 °C for 2 h under an Ar atmosphere). Ti-6Al-4V ELI alloy tensile specimens in both the horizontal (i.e., X and Y) and vertical (Z) directions were produced by the laser powder bed fusion (LPBF) technique. Higher yield strength (1141 MPa), higher tensile strength (1190 MPa), but lower elongation at fracture (6.9%), along with mechanical anisotropy were observed for as-stress-relieved (ASR) samples. However, after HIP, consistent and isotropic mechanical behaviors were observed with a slight reduction in yield strength (928 MPa) and tensile strength (1003 MPa), but with a significant improvement in elongation at fracture (16.1%). Phase constituents of acicular α' phase in ASR and lamellar α + β phases in HIP samples were observed and quantified to corroborate the reduction in strength and increase in ductility. The anisotropic variation in elongation at fracture observed for the ASR samples, particularly built in the build (Z) direction, was related to the presence of “keyhole” porosity.

42 ENGINEERING↗
DOE OSTI2021

Investigation of Machinability of Additively Manufactured Ti-6Al-4V

Additively manufactured metals differ from their conventionally produced counterparts due to the inherent material inhomogeneity, porosity, and thermal stress induced by the process. These differences make the machining of additively manufactured metals more difficult and cause premature tool failure or unexpected surface finish at certain conditions. This study takes the first step to investigate and identify the causes of these issues, particularly for Ti-6Al-4V. Printed and wrought samples, as well as heat treatment effect, are compared in a dry cutting condition at a cutting speed of 90 m/min in terms of cutting power, vibration, temperature, and produced surface finish. The results show a lower cutting power and more vibration for as-printed Ti samples, indicating a less ductile microstructure and inclusion of pores. Heat treatment can eliminate these phenomena. There is no significant difference found in the produced surface finish at the current cutting condition.

Raval, Jay↗
DOE OSTI2025

Pursuing small-scale measures of penetration resistance in Ti-5553 alloy

This work was originally proposed to illustrate the performance of a particular set of differently processed Ti-5553 plates under dynamic threats. It became clear that the larger question, at present, is whether the small-scale shaped charge design of an RP-4 detonator can be employed to efficiently explore the dynamic penetration resistance of representative test articles. The initial penetration testing that employed three variants of thermomechanical processing of Ti-5553 plates appeared to demonstrate that there was a noticeable difference in their performance. The remaining pertinent question was regarding the variation in the shaped charge performance and how it compares to the variation from the three titanium plate tests. Based on the limited testing presented here the RP-4 shaped charge detonator appears to have an average depth of penetration in 6061 aluminum of 90mm with a 1.5CD stand off.

shaped charge penetration↗
DOE OSTI2021

Texture evolution as a function of scan strategy and build height in electron beam melted Ti-6Al-4V

Metal additive manufacturing (AM) enables customizable, on-demand parts, allowing for new designs and improved engineering performance. Yet, the ability to control AM metal alloy microstructures (i.e., grain morphology, crystallographic texture, and phase content) is lacking. Furthermore, this work performs corroborative neutron diffraction and large-scale electron backscatter diffraction (EBSD) measurements to assess crystallographic texture in electron beam melted (EBM) Ti-6Al-4V as a function of scan strategy and build height. Texture components for one raster and two spot melt scan strategies were evaluated using a triclinic specimen symmetry to capture all possible texture components, which were found to be considerably different than previously reported values from studies employing orthotropic specimen symmetry. This finding highlights the importance of a standard method and best practice for assessing textures produced by AM.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ti(PS3)2 by Materials Project

TiP2S6 crystallizes in the orthorhombic Fdd2 space group. The structure is three-dimensional. Ti2+ is bonded in an octahedral geometry to six S2- atoms. There are two shorter (2.43 Å) and four longer (2.46 Å) Ti–S bond lengths. P5+ is bonded in a trigonal non-coplanar geometry to three S2- atoms. There are a spread of P–S bond distances ranging from 2.02–2.05 Å. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded in an L-shaped geometry to one Ti2+ and one P5+ atom. In the second S2- site, S2- is bonded in a water-like geometry to one Ti2+ and one P5+ atom. In the third S2- site, S2- is bonded in an L-shaped geometry to one Ti2+ and one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ti(MnP6)2 by Materials Project

TiMn2P12 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Ti4+ is bonded in a 8-coordinate geometry to eight P+0.67- atoms. There are a spread of Ti–P bond distances ranging from 2.55–2.71 Å. Mn2+ is bonded to six P+0.67- atoms to form MnP6 octahedra that share corners with five PTiP3 tetrahedra and an edgeedge with one MnP6 octahedra. There are a spread of Mn–P bond distances ranging from 2.20–2.33 Å. There are six inequivalent P+0.67- sites. In the first P+0.67- site, P+0.67- is bonded in a distorted single-bond geometry to one Mn2+ and three P+0.67- atoms. There are a spread of P–P bond distances ranging from 2.20–2.24 Å. In the second P+0.67- site, P+0.67- is bonded to one Ti4+ and three P+0.67- atoms to form distorted PTiP3 tetrahedra that share corners with four equivalent MnP6 octahedra and corners with four PTiP3 tetrahedra. The corner-sharing octahedra tilt angles range from 54–72°. There are a spread of P–P bond distances ranging from 2.22–2.31 Å. In the third P+0.67- site, P+0.67- is bonded in a 4-coordinate geometry to one Ti4+, one Mn2+, and two P+0.67- atoms. The P–P bond length is 2.21 Å. In the fourth P+0.67- site, P+0.67- is bonded to one Ti4+, one Mn2+, and two P+0.67- atoms to form distorted PTiMnP2 tetrahedra that share a cornercorner with one MnP6 octahedra and corners with four PTiP3 tetrahedra. The corner-sharing octahedral tilt angles are 67°. The P–P bond length is 2.28 Å. In the fifth P+0.67- site, P+0.67- is bonded in a 4-coordinate geometry to one Ti4+, one Mn2+, and two P+0.67- atoms. In the sixth P+0.67- site, P+0.67- is bonded in a 2-coordinate geometry to two equivalent Mn2+ and two P+0.67- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ti(SnO2)2 by Materials Project

Sn2TiO4 crystallizes in the tetragonal P4_2/mbc space group. The structure is three-dimensional. Ti4+ is bonded to six O2- atoms to form edge-sharing TiO6 octahedra. There is two shorter (1.99 Å) and four longer (2.00 Å) Ti–O bond length. Sn2+ is bonded in a 3-coordinate geometry to three O2- atoms. There are two shorter (2.12 Å) and one longer (2.24 Å) Sn–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to one Ti4+ and two equivalent Sn2+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Ti4+ and one Sn2+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ti(Bi3O5)4 by Materials Project

Bi12TiO20 crystallizes in the cubic I23 space group. The structure is three-dimensional. Ti4+ is bonded in a tetrahedral geometry to four equivalent O2- atoms. All Ti–O bond lengths are 1.85 Å. Bi3+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Bi–O bond distances ranging from 2.11–2.65 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three equivalent Bi3+ atoms. In the second O2- site, O2- is bonded in a distorted single-bond geometry to one Ti4+ and three equivalent Bi3+ atoms. In the third O2- site, O2- is bonded in a trigonal planar geometry to three equivalent Bi3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ti(SiO3)2 by Materials Project

TiSi2O6 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Ti4+ is bonded to six O2- atoms to form distorted TiO6 octahedra that share corners with six equivalent SiO4 tetrahedra and edges with two equivalent TiO6 octahedra. There are a spread of Ti–O bond distances ranging from 1.84–2.17 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three equivalent TiO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 30–58°. There are a spread of Si–O bond distances ranging from 1.62–1.66 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Ti4+ and one Si4+ atom. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to one Ti4+ and one Si4+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Si4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ti(CuS)4 by Materials Project

Cu4(TiS4) crystallizes in the tetragonal I-42m space group. The structure is three-dimensional. Ti4+ is bonded to four equivalent S2- atoms to form TiS4 tetrahedra that share corners with four equivalent CuS4 tetrahedra and edges with six CuS4 tetrahedra. All Ti–S bond lengths are 2.30 Å. There are two inequivalent Cu1+ sites. In the first Cu1+ site, Cu1+ is bonded to four equivalent S2- atoms to form CuS4 tetrahedra that share corners with twelve CuS4 tetrahedra and edges with two equivalent TiS4 tetrahedra. All Cu–S bond lengths are 2.34 Å. In the second Cu1+ site, Cu1+ is bonded to four equivalent S2- atoms to form CuS4 tetrahedra that share corners with two equivalent TiS4 tetrahedra, corners with twelve CuS4 tetrahedra, and an edgeedge with one TiS4 tetrahedra. There are two shorter (2.32 Å) and two longer (2.35 Å) Cu–S bond lengths. S2- is bonded to one Ti4+ and four Cu1+ atoms to form a mixture of distorted corner and edge-sharing STiCu4 trigonal bipyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ti(FeO2)2 by Materials Project

Fe2TiO4 is Spinel-like structured and crystallizes in the orthorhombic Imma space group. The structure is three-dimensional. Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with six equivalent FeO4 tetrahedra, edges with two equivalent TiO6 octahedra, and edges with four equivalent FeO6 octahedra. There is two shorter (1.97 Å) and four longer (2.02 Å) Ti–O bond length. There are two inequivalent Fe2+ sites. In the first Fe2+ site, Fe2+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with six equivalent TiO6 octahedra and corners with six equivalent FeO6 octahedra. The corner-sharing octahedra tilt angles range from 52–62°. There are two shorter (2.03 Å) and two longer (2.07 Å) Fe–O bond lengths. In the second Fe2+ site, Fe2+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six equivalent FeO4 tetrahedra, edges with two equivalent FeO6 octahedra, and edges with four equivalent TiO6 octahedra. There are four shorter (2.13 Å) and two longer (2.21 Å) Fe–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ti4+ and two Fe2+ atoms. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Ti4+ and three Fe2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ti(CoO2)2 by Materials Project

Co2TiO4 is Spinel-like structured and crystallizes in the orthorhombic Imma space group. The structure is three-dimensional. Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with six equivalent CoO4 tetrahedra, edges with two equivalent TiO6 octahedra, and edges with four equivalent CoO6 octahedra. There is two shorter (1.97 Å) and four longer (2.01 Å) Ti–O bond length. There are two inequivalent Co2+ sites. In the first Co2+ site, Co2+ is bonded to four O2- atoms to form CoO4 tetrahedra that share corners with six equivalent TiO6 octahedra and corners with six equivalent CoO6 octahedra. The corner-sharing octahedra tilt angles range from 55–60°. There is two shorter (1.97 Å) and two longer (2.02 Å) Co–O bond length. In the second Co2+ site, Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with six equivalent CoO4 tetrahedra, edges with two equivalent CoO6 octahedra, and edges with four equivalent TiO6 octahedra. There are four shorter (2.08 Å) and two longer (2.17 Å) Co–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a rectangular see-saw-like geometry to two equivalent Ti4+ and two Co2+ atoms. In the second O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ti4+ and three Co2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ti(TlS)4 by Materials Project

Tl4TiS4 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Ti4+ is bonded in a tetrahedral geometry to four S2- atoms. There are a spread of Ti–S bond distances ranging from 2.26–2.29 Å. There are four inequivalent Tl1+ sites. In the first Tl1+ site, Tl1+ is bonded in a 6-coordinate geometry to four S2- atoms. There are a spread of Tl–S bond distances ranging from 2.98–3.37 Å. In the second Tl1+ site, Tl1+ is bonded in a 5-coordinate geometry to five S2- atoms. There are a spread of Tl–S bond distances ranging from 3.02–3.86 Å. In the third Tl1+ site, Tl1+ is bonded in a 5-coordinate geometry to five S2- atoms. There are a spread of Tl–S bond distances ranging from 2.97–3.77 Å. In the fourth Tl1+ site, Tl1+ is bonded in a 4-coordinate geometry to four S2- atoms. There are a spread of Tl–S bond distances ranging from 2.99–3.46 Å. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded to one Ti4+ and four Tl1+ atoms to form distorted corner-sharing STiTl4 trigonal bipyramids. In the second S2- site, S2- is bonded in a 1-coordinate geometry to one Ti4+ and four Tl1+ atoms. In the third S2- site, S2- is bonded in a 1-coordinate geometry to one Ti4+ and five Tl1+ atoms. In the fourth S2- site, S2- is bonded in a 1-coordinate geometry to one Ti4+ and five Tl1+ atoms.

36 MATERIALS SCIENCE↗