Micrometric rods grown by nanosecond pulsed laser deposition of boron carbide

Lopez-Quintas, Ignacio; Oujja, M.; Sanz, Mikel; Benítez-Cañete, A.; Chater, Richard J.; Cañamares, María Vega; Marco, José F.; Castillejo, Marta

doi:10.1016/j.apsusc.2014.12.035

Cited by 11 publications

(3 citation statements)

References 36 publications

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“…Ti–H stretching modes are expected to arise in the range of 1400–1600 cm –1 but could not be assigned unambiguously. Nevertheless, these new features formed upon exposing Ti–Al–B NP-doped JP-10 to focused 532 nm light reveal an active photochemistry at 532 nm. − …”

Section: Resultsmentioning

confidence: 97%

Combined Spectroscopic and Computational Investigation on the Oxidation of exo-Tetrahydrodicyclopentadiene (JP-10; C₁₀H₁₆) Doped with Titanium–Aluminum–Boron Reactive Metal Nanopowder

et al. 2021

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We report the results on the combustion of single, levitated droplets of exo-tetrahydrodicyclopentadiene (JP-10) doped with titanium−aluminum−boron (Ti−Al−B) reactive metal nanopowders (RMNPs) in an oxygen (60%)−argon (40%) atmosphere by exploiting an ultrasonic levitator with droplets ignited by a carbon dioxide laser. Ultraviolet−visible (UV−vis) emission spectroscopy revealed the presence of gas-phase aluminum (Al) and titanium (Ti) atoms. These atoms can be oxidized in the gas phase by molecular oxygen to form spectroscopically detected aluminum monoxide (AlO) and titanium monoxide (TiO) transients. Analysis of the optical ignition videos supports that the nanoparticles are ignited before JP-10. The detection of boron monoxide (BO) further proposes an active surface chemistry through the oxidation of the RMNPs and the release of at least BO into the gas phase. The oxidation of gas-phase BO by molecular oxygen to boron dioxide (BO 2 ) plus atomic oxygen might operate in the gas phase, although the involvement of surface oxidation processes of RMNPs to BO 2 cannot be discounted. The UV−vis emission spectra also revealed the key reactive intermediates (OH, CH, C 2 , and HCO) of the oxidation of JP-10. Electronic structure calculations reveal that the presence of reactive radicals has a profound impact on the oxidation of JP-10. Although titanium monoxide (TiO) reacts to produce titanium dioxide (TiO 2 ), it does not engage in an active JP-10 chemistry as all abstraction pathways are endoergic by more than 217 kJ mol −1 . This is similar for atomic aluminum and titanium, whose hydrogen abstraction reactions from JP-10 were revealed to be endoergic by at least 77 kJ mol −1 . Therefore, aluminum and titanium react preferentially with molecular oxygen to produce their monoxides. However, the formation of BO, AlO, and BO 2 supplies a pool of highly reactive radicals, which can abstract hydrogen from JP-10 via transition states ranging from only 1 to 5 kJ mol −1 above the separated reactants, forming JP-10 radicals along with the hydrogen abstraction products (boron hydride oxide, aluminum monohydroxide, and metaboric acid) in the overall exoergic reactions. These abstraction barriers are well below the barriers of abstractions for ground-state atomic oxygen and molecular oxygen. In this sense, gas-phase BO, AlO, and BO 2 catalyze the oxidation of gas-phase JP-10 via hydrogen abstraction, forming highly reactive JP-10 radicals. Overall, the addition of RMNPs to JP-10 not only provides a higher energy density fuel but is also expected to lead to shorter ignition delays compared to pure JP-10 due to the highly reactive pool of radicals (BO, AlO, and BO 2 ) formed in the initial stage of the oxidation process.

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Section: Resultsmentioning

confidence: 97%

Combined Spectroscopic and Computational Investigation on the Oxidation of exo-Tetrahydrodicyclopentadiene (JP-10; C₁₀H₁₆) Doped with Titanium–Aluminum–Boron Reactive Metal Nanopowder

et al. 2021

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“…32 Oxy-boron carbon appears around 190.9 eV. 33 The peak at 187.9 eV represents B-B bonding in the boron cluster. The lower binding energy peak demonstrates that the boron atoms are surrounded by more atoms with lower electronegativity.…”

Section: Resultsmentioning

confidence: 99%

“…Boron atoms in oxides are associated with B 2 O 3 and BCO 2 , which have binding energies around 193.2 and 192.0 eV, respectively 32 . Oxy‐boron carbon appears around 190.9 eV 33 . The peak at 187.9 eV represents B–B bonding in the boron cluster.…”

Section: Resultsmentioning

confidence: 99%

Densification of low‐density boron carbide by Li doping and its microstructural characterization

Pan,

Wang,

Zhang

et al. 2024

J Am Ceram Soc.

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Lithium (Li)‐doped boron carbide (B4C) has generated widespread attention for its potential to enhance mechanical properties. Nevertheless, the influence of the Li solid solution on the microstructure and mechanical properties of B4C ceramics remain unclear. In this research, the microstructure of Li‐doped B4C was investigated in meticulous detail. Through X‐ray diffraction, X‐ray photoelectron spectroscopy, and Raman spectroscopy analysis, it was confirmed that Li successfully solubilized in B4C at 1 500°C under 50 MPa for an 8 min, resulting in lattice expansion. Further insights from electron energy loss spectroscopy revealed the integration of Li into the crystal lattice and alterations in the C–B–C chains. Furthermore, the Li2O content significantly affected the densification and microstructure of B4C. Relative density increased from 91.2% (B4C) to 99.2% (9 wt.% Li2O–B4C), accompanied by a transition from a few intragranular planar defects to high‐density twins. Mechanical property tests demonstrated that 9 wt.% Li2O–B4C exhibited optimal comprehensive mechanical performance, with a flexural strength of 533 ± 27 MPa, fracture toughness of 3.71 ± 0.29 MPa∙m1/2, hardness of 33.3 ± 0.6 GPa, and a density of just 2.45 g/cm3, surpassing that of pure B4C.

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Nonlinear Optics in Laser Ablation Plasmas

Oujja¹,

Sanz²,

Nalda³

et al. 2018

Advances in the Application of Lasers in Materials Science

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Micrometric rods grown by nanosecond pulsed laser deposition of boron carbide

Cited by 11 publications

References 36 publications

Combined Spectroscopic and Computational Investigation on the Oxidation of exo-Tetrahydrodicyclopentadiene (JP-10; C₁₀H₁₆) Doped with Titanium–Aluminum–Boron Reactive Metal Nanopowder

Combined Spectroscopic and Computational Investigation on the Oxidation of exo-Tetrahydrodicyclopentadiene (JP-10; C₁₀H₁₆) Doped with Titanium–Aluminum–Boron Reactive Metal Nanopowder

Densification of low‐density boron carbide by Li doping and its microstructural characterization

Nonlinear Optics in Laser Ablation Plasmas

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Micrometric rods grown by nanosecond pulsed laser deposition of boron carbide

Cited by 11 publications

References 36 publications

Combined Spectroscopic and Computational Investigation on the Oxidation of exo-Tetrahydrodicyclopentadiene (JP-10; C10H16) Doped with Titanium–Aluminum–Boron Reactive Metal Nanopowder

Combined Spectroscopic and Computational Investigation on the Oxidation of exo-Tetrahydrodicyclopentadiene (JP-10; C10H16) Doped with Titanium–Aluminum–Boron Reactive Metal Nanopowder

Densification of low‐density boron carbide by Li doping and its microstructural characterization

Nonlinear Optics in Laser Ablation Plasmas

Contact Info

Product

Resources

About

Combined Spectroscopic and Computational Investigation on the Oxidation of exo-Tetrahydrodicyclopentadiene (JP-10; C₁₀H₁₆) Doped with Titanium–Aluminum–Boron Reactive Metal Nanopowder

Combined Spectroscopic and Computational Investigation on the Oxidation of exo-Tetrahydrodicyclopentadiene (JP-10; C₁₀H₁₆) Doped with Titanium–Aluminum–Boron Reactive Metal Nanopowder