Effect Of Boron Content Research Articles

Control on nanostructured quaternary Ti–Al–O–B composite synthesized via electrospinning method, from nanoparticles to nanowhiskers

The nanostructured powder of multicomponent oxides, borides, and borates is widely used due to its high hardness, corrosion resistance, high melting point, insulating, and abrasive. In the present work, the effect of boron content on the morphology of electrospun multicomponent oxide, boride, and borate nanostructures in a quaternary Ti–Al–O–B system was investigated. Different molar ratios of B/(Ti + Al) (0.8, 1.6, and 2.4) were employed and evaluated. Imaging with the field emission scanning electron microscope (FESEM) and the transmission electron microscope (TEM) revealed that after one hour of thermal treatment at 1100 °C, the hybrid electrospun nanofibers (NFs) in the fibrous platform transformed into nanoparticles (NPs), nano-needles, and nano-whiskers at B/(Ti + Al) molar ratios of 0.8, 1.6, and 2.4, respectively. The binding energies were investigated by X-ray photoelectron spectroscopy (XPS), whereas the phase study was conducted via the X-ray diffraction (XRD) technique. The results confirmed the formation of nanostructured ceramic powder platforms composed of multiple components, namely oxides (e.g., B-doped TiO2; Al2O3), borides (TiB, TiB2, Ti2B5, TiB12, and AlB2), and borates (TiBO3; Al18B4O33). Simultaneous thermal analysis (STA) of the Ti–Al–O–B mats indicated that the borides and borates formed consecutively at temperatures above 800 °C through reactions involving molten B2O3. We found that the obtained NPs were well arranged and sintered together throughout the fibers.

High entropy alloy borides prepared by powder metallurgy process and the enhanced fracture toughness by addition of yttrium

High entropy alloy borides FeCoNiAlCrBx (x = 0.5 and 1.0 in molar ratio) were prepared by high energy ball milling and spark plasma sintering (SPS). Pure high entropy alloy FeCoNiAlCr was prepared for comparison. The effect of boron content on alloying behavior, phase composition, microstructure, micro hardness, and fracture toughness of the as-prepared samples were studied. The results showed that, with the increase of boron content, the hardness of FeCoNiAlCr alloy increased significantly in the cost of embrittlement due to decrease/disappear of FCC phase as well as the formation/increase of borides enriched in Fe and Cr elements. The borides were found to be distributed uniformly at the grain boundaries. The toughness of FeCoNiAlCrB was found to be increased by about 40% with only small sacrifice of hardness when 0.1 molra ratio of Yttrium (Y) was introduced. The enhanced fracture toughness could be probably attributed to the more uniformly distribution of brittle borides phases and the increase of the solid solution of boron in the alloy.

Effects of boron content on the microstructure and mechanical properties of twin-roll strip casting borated steel sheets

High borated steel sheets containing 0.25 wt% to 4.0 wt% boron including hypoeutectic (0.28 wt% B and 2.11 wt% B), eutectic (2.43 wt% B) and hypereutectic (4.01 wt% B) compositions were tried to be fabricated by a novel strip casting technology, and the effects of boron content on sub-rapid solidification behavior and subsequent microstructural evolution together with mechanical properties was studied. It was found that the morphology of borides depended greatly on the boron content. When increasing boron, the morphological change of borides was network-like → grainy → cluster-like → plate-like. Various orientation relationships between different morphological borides and γ-Fe in as-cast steels were also identified. After subsequent hot-rolling and solution-treating, ultra-fine (<10 μm) borides were obtained in hypoeutectic and eutectic steels. Benefiting from that, excellent mechanical properties was achieved, which was much better than that of steels prepared by traditional ingot casting. Particularly, when the boron content approached eutectic composition, of which the effect on the microstructure and mechanical properties was more sensitive. The steels containing 2.11 wt% and 2.43 wt% boron exhibited different morphological borides with a total elongation of 14.1% and 8.0%, respectively. Moreover, a thin hypereutectic borated steel sheet was also prepared, but the borides were very large and the total elongation was very low. The correlation between microstructure and strength was clarified based on the Hall-Petch behavior and intermetallic strengthening effect. Smaller γ-grains and higher volume fraction of borides were responsible for higher strength. The plastic behavior of steels was influenced by strain-hardening rate that was determined by the volume fraction of γ-Fe matrix. A better sustainable strain-hardening capability was beneficial to extend the stage of uniform deformation and enhance the ductility. In addition, the mechanical properties of steels were also decided by the fracture mechanism that was dominated by the size of borides.

Effect of boron content on the structure, mechanical and tribological properties of sputtered Mo–S–B films

Molybdenum disulfide (MoS2) is a widely applied solid lubricant due to its unique layered structure. However, low hardness and environmental sensitivity severely limit its practical application in industry. Here, Mo–S–B films were deposited on Si (100) substrates by magnetron sputtering. The structure, mechanical and tribological properties showed a significant dependency on composition and chemical bonding. Increasing the B content from 0 to 23.4 at.%, the surface became smooth, corresponding to a transition from columnar structure to dense feature, along with a phase transition from hexagonal-MoS2 to amorphous phase. The hardness lineally increased from 0.75 GPa for MoS2 to 8.38 GPa for the Mo–S–B film with 23.4 at.% B. The tribological properties of films were evaluated against steel ball using ball-on-disc tribometer. The tribological test results indicated that the increased B content led to the enhancement of wear resistance for Mo–S–B films, the wear rate of Mo–S–B films with 23.4 at.% B showed the lowest value of 5.5 × 10−7 mm3/Nm, which was two orders of magnitude lower than pure MoS2 (5.66 × 10−5 mm3/Nm). The friction coefficient just rose slightly, keeping it at the same level as pure MoS2. Raman analysis for wear debris after rubbing revealed that MoS2 tribofilm improved lubrication behavior.

Effect of Boron Content and Cooling Rate on the Microstructure and Boride Formation of β-Solidifying γ-TiAl TNM Alloy

Boron is a unique and popular grain refiner element in cast titanium aluminide (TiAl) alloys, as it helps to improve mechanical properties if properly alloyed. However, the formation mechanism of different types of borides in cast TiAl alloys is not yet clearly understood. This study seeks to correlate the chemical composition and cooling rate during solidification of cast TiAl alloys, with the type of boride precipitated and the resulting microstructure. Several β-solidifying γ-TiAl alloys of the TNM family were cast, alloying boron to a starting Ti-44.5Al-4Nb-1Mo-0.1B (at.%) alloy. The alloys were manufactured with an induction skull melting furnace and poured into a stepped 2, 4, 8 and 16 mm thickness mold to achieve different cooling rates. On one hand, the results reveal that boron contents below 0.5 at.% and cooling rates during solidification above 10 K/s promote the formation of detrimental ribbon borides. On the other hand, boron contents above 0.5 at.% and cooling rates during solidification below 10 K/s promote the formation of a refined microstructure with blocky borides. Finally, the formation mechanisms of both ribbon and blocky borides are proposed.

Effects of boron content on the microwave‐transparent property and high‐temperature stability of continuous SiBN fibers

AbstractOwing to their high‐temperature stability and microwave‐transparent properties, SiBN fibers are promising reinforcement materials for microwave windows or radomes in harsh environments. This work investigates the high‐temperature properties of continuous SiBN fibers with different boron contents. Compared with Si3N4 fibers, the SiBN fibers demonstrated superior high‐temperature stability, retaining their original tensile strength up to 1600°C with a smooth surface and amorphous structure. The boron‐containing microstructure improved the microwave‐transparent properties of the SiBN fibers by decreasing their dielectric constant and loss. The values were stabilized at temperatures up to 1200°C. The high‐temperature stability and microwave transparency of the SiBN fibers were likely contributed by the synergistic effect of the amorphous BN phase and the Si–N–B networks (the main existing state of the boron atoms).

Influence of in-situ synthesized carboborides on microstructure evolution and the wear resistance of laser clad Fe-base composite coatings

The carboboride reinforced Fe-base composite coatings were prepared to improve the abrasive wear resistance of 42CrMo by laser cladding. The compositions of the coatings were high-speed steel with high boron contents. The effects of boron content on the microstructure, hardness, and wear behaviors of the coatings were focused. The microstructure evolution and phase transformation were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), electron probe micro-analyzer (EPMA), and transmission electron microscope (TEM). The results showed that the types and morphologies of hard phases in the coatings were influenced by boron content. The MC, M2C, and M6C carbides were observed in the coating without boron addition; while M23(B, C)6 and residual M3(B, C) existed in the coating when boron was added. The eutectic structure consisted of M23(B, C)6, residual M3(B, C), and matrix appeared at the grain boundary when the boron content exceeded 0.75% (wt%). The hardness and wear resistance of the coatings improved with the increasing boron content. But when the boron content was up to 1%, cracks would occur in the coating. The hardness of the best coating with 0.75% boron addition reached 8.95 GPa, which was 2.6 times that of the 42CrMo substrate. The wear weight loss of the coating with 0.75% boron addition was 0.0965 g, which was only 10% that of the 42CrMo substrate.

Different aspect of solidification cracking susceptibility and hot ductility behavior of borated stainless steels and the effects of boron content

A series of austenitic Fe-0.06wt%C-1.5wt%Mn-18wt%Cr-12wt%Ni stainless steels with B additions ranging from 0.2 to 1.76 wt% were prepared and the weldability of these samples was evaluated through Varestraint cracking tests and Gleeble hot ductility tests. The base steels consisted of the austenite(γ) matrix and borides of Cr-enriched M2B (Cr2B), and the fraction and size of the Cr2B borides increased with an increase in the B content. The results of the Varestraint cracking tests indicated that the resistance to solidification cracking in the fusion zone was improved with an increase in the B content and this is because the extent of solidification temperature range reduces with an increase in the B content. In the fusion zone, cracks occurred at the interphase between the primary γ and γ/Cr2B eutectic during solidification. At the heat-affected zone (HAZ) near the fusion zone, constitutional liquation occurred around the Cr2B borides, after which the γ/Cr2B eutectic formed surrounding Cr2B borides during cooling. Interestingly, the results of the hot ductility tests were in direct contrast to those of the Varestraint cracking tests; i.e., the hot ductility in the HAZ decreased with an increase in the B content. This occurred because cracks initiated and propagated along the γ/Cr2B interphase, and then the fraction and size of the brittle Cr2B borides acted as crack initiation site increased with an increase in the B content.

Effects of Boron Content on Microstructure and Mechanical Properties of TiAlSiBxN Nanocomposite Films

The TiAlSiBN nanocomposite films with the boron (B) content ranging from 1.95 at.% (atom percent) to 10.58 at.% were synthesized by reactive magnetron sputtering. The effects of B content on the microstructure and mechanical properties of TiAlSiBxN films were studied by x-ray diffraction, high-resolution transmission electron microscopy, scanning electron microscopy and nanoindentation techniques. The results show that the nanocomposite structure forms within the TiAlSiBxN films. With the increase in B content, the crystallinity and mechanical properties first increase and then decrease. When the B content (x) rises to 0.12, a coherent growth structure is created between nanocrystallites and interfaces, leading to the improvement of crystallinity and effective strengthening effect, with the maximal hardness and elastic modulus of 38.9 and 391 GPa, respectively. The TiAlSiBN nanocomposite films present potential industrial applications as a protective coating.

Effect of boron content in B·BiF3 and B·Bi composites on their ignition and combustion

Composite powders combining boron with BiF3 and Bi in different amounts were prepared by high energy milling. Thermal analysis in an argon-oxygen mixture showed significant oxidation starting about 200 K lower than for pure boron. Selective oxidation of metallic Bi at low temperatures was observed. Composites containing either Bi or BiF3 ignited more readily than pure boron when heated by a CO2 laser beam. The composites containing BiF3 ignited more readily than boron when in contact with a hot wire. Burn times of particles aerosolized in air and ignited using the CO2 laser were measured as durations of the recorded emission pulses produced by burning particles. Statistical distributions of the measured burn times were correlated with the respective powder's particle size distributions. Compared to elemental boron, burn times of all prepared composites were shorter, including those containing only 10 wt.% of BiF3 or ca. 8 wt.% of Bi, and for most composites combustion temperatures were higher.

Effects of Boron Content on Microstructure and Wear Properties of FeCoCrNiBx High-Entropy Alloy Coating by Laser Cladding

The FeCoCrNiBx high-entropy alloy (HEA) coatings with three different boron (B) contents were synthesized on Q245R steel (American grade: SA515 Gr60) by laser cladding deposition technology. Effects of B content on the microstructure and wear properties of FeCoCrNiBx HEA coating were investigated. In this study, the phase composition, microstructure, micro-hardness, and wear resistance (rolling friction) were investigated by X-ray diffraction (XRD), a scanning electron microscope (SEM), a micro hardness tester, and a roller friction wear tester, respectively. The FeCoCrNiBx coatings exhibited a typical dendritic and interdendritic structure, and the microstructure was refined with the increase of B content. Additionally, the coatings were found to be a simple face-centered cubic (FCC) solid solution with borides. In terms of mechanical properties, the hardness and wear resistance ability of the coating can be enhanced with the increase of the B content, and the maximum hardness value of three HEA coatings reached around 1025 HV0.2, which is higher than the hardness of the substrate material. It is suggested that the present fabricated HEA coatings possess potentials in application of wear resistance structures for Q245R steel.

Network polymerization and cation coordination environments in boron-bearing rhyolitic melts: Insights from 17O, 11B, and 27Al solid-state NMR of sodium aluminoborosilicate glasses with varying boron content

Despite the geochemical implications for the dissolution behaviors of nuclear waste glasses and the properties of boron-bearing rhyolitic melts, a detailed atomic-level understanding of the overall effect of boron content on the structural characteristics of boron-bearing silicate glasses remains elusive. Herein, we explore the effects of B/Al and Si/B ratios on the local configurations around cations and the degree of network polymerization of Na2O-Al2O3-B2O3-SiO2 glasses in nepheline (NaAlSiO4) – malinkoite (NaBSiO4) and albite (NaAlSi3O8) – reedmergnerite (NaBSi3O8) joins using multi-nuclear magnetic resonance (NMR). The 11B NMR results confirmed an increase in the B coordination numbers from 3 ([3]B) to 4 ([4]B) as B/Al and Si/B ratios increase. The 27Al NMR spectra show that the Al is mainly four coordinated, except in NaAl0.25B0.75SiO4 glasses, with a minor amount of [5]Al species, revealing a more prominent control of Si over that of B on the Al coordination environments. The 17O NMR spectra resolve distinct bridging (BO, Si−O−Al, Al−O−Al, Si−O−Si, B−O−B, and Si−O−B) and non-bridging oxygens (NBO, Na−O−Si). In contrast, the absence of B−O−Al species confirmed the separation between B and Al and prevalent melt depolymerization exclusively in silicate-networks. The fractions of B−O−B and Na−NBO increase as B/Al ratio increases, accounting for a drastic enhancement in the dissolution rate of glasses. A dramatic increase also indicates an enhanced connectivity of relatively weaker bonds such as B−O−B and Na−O−Si as composition reached a certain boron content. This is linked to a decrease in the melt viscosity with increasing B2O3 component. Based on the measured fractions of [3,4]B in 11B NMR spectra with varying composition, the trend of the evolution of boron isotope composition in sodium aluminoborosilicate melts was estimated, confirming the preferential enrichment of 10B into rhyolitic melts with increasing boron content. The decreased fraction of [3]B species with increasing Si/B may partly explain the reduction in δ11B in boron-bearing volcanic rocks at deeper depths in the subduction zone. The results suggest that composition-induced changes in the atomic structures should be constrained to precisely interpret the melt viscosity, boron isotope composition of arc volcanic lavas, and the dissolution rates of nuclear waste glasses.

In-situ synthesis and densification of CeB6 ceramics by spark plasma sintering from CeO2 and B powders: Effect of boron content and boron particle size on microstructural, mechanical and electrical properties

In-situ synthesis and densification of polycrystalline bulk CeB6 ceramics were carried out by Spark Plasma Sintering technique using CeO2 and coarse & nano B powders. Two-step heating schedule was applied via optimizing both synthesis and sintering temperatures using FactSage thermochemical software. The influence of boron particle size and content on the physical, microstructural, mechanical and electrical properties of CeB6 ceramics were investigated. The obtained results exhibited that the content of additional phases (B2O3 & B4C) decreased with the decreasing of boron content (from 31.5 to 23.5 wt%). The reduction of boron particle size (from 1 μm to 250 nm) enhanced fracture toughness values of the investigated ceramics. CeB6 ceramic sintered using nano boron in 8 wt% lack ratio possessed highest CeB6 content (98.4 vol%), high hardness (16.0 ± 2.0 GPa), high fracture toughness (2.8 ± 0.5 MPa m1/2) and low electrical resistivity (1.58x10−1 Ω m). Hence, polycrystalline bulk CeB6 ceramics, sintered at 1950 °C for 15 min under 15 kN by SPS from CeO2 - coarse B powder mixture in 8 wt % lack B ratio, have a usage potential as electron emitters especially in electron microscopes.

Effects of boron content on the microstructures and mechanical properties of reactive hot-pressed BxC-TiB2-SiC composites

Abstract BxC-TiB2-SiC ceramic composites were fabricated via reactive hot pressing using TiC, B, and Si as the raw materials. The phase transition process was studied by heating powder mixtures to different temperatures in combination with X-ray diffraction analysis. The stoichiometric ratio between B and C in boron carbide is variable. A series of powder mixtures containing excess boron (0 wt%, 10 wt%, 20 wt%, or 30 wt% B) were sintered, and the microstructures and mechanical properties of the composites were investigated. The results showed that the B6.1C-TiB2-SiC composite prepared from the starting powders with 30 wt% excess boron had the best comprehensive mechanical properties, with a relative density, hardness, bending strength, and fracture toughness of 98.32%, 33.2 GPa, 840 MPa, and 5.22 MPa m1/2, respectively. Excessive boron substitution may cause lattice distortion in boron carbide, and the boron carbide grains in this state may form a large number of twins under the compressive stress generated by the TiB2 grains, which will affect the properties of the composites.

Effects of boron content on environmental embrittlement of ordered Ni3Fe alloys

The effects of boron content (CB = 0–0.14% (mass fraction)) on the tensile properties and environmental embrittlement of ordered Ni-24%Fe (atom fraction)-B (Ni3Fe-B) alloys have been investigated using tensile tests in vacuum and under gaseous hydrogen. The results indicate that, when CB < 0.06% (mass fraction), the tensile strength and elongation of the alloys in vacuum and gaseous hydrogen increase as CB in the ordered Ni3Fe-B alloy increases. The tensile strength and elongation are maximum, and the hydrogen embrittlement factor (IH) is minimum for the ordered Ni3Fe-0.06%B (mass fraction) alloy. Compared with the ordered B-free Ni3Fe alloy, IH of the ordered Ni3Fe-0.06%B (mass fraction) alloy decreases by 98.1%, and the fracture morphology of the alloy changes from fully intergranular to fully transgranular, when tested in gaseous hydrogen. A critical level of boron segregation at the grain boundaries of ordered Ni3Fe-B alloys is observed. The hydrogen embrittlement of ordered Ni3Fe-B alloys in gaseous hydrogen can be completely suppressed by boron atoms when CB $$\geqslant$$ 0.06% (mass fraction).

Effects of Boron Content on microstructure and mechanical properties of AlFeCoNiBx High Entropy Alloy Prepared by vacuum arc melting

The AlFeCoNiBx (x = 0, 0.05, 0.10, 0.15, 0.2) high entropy alloys are prepared by vacuum arc melting. The effect of B on the microstructure and mechanical behaviors of the alloys are systematically investigated. X-Ray Diffraction results and Electro-Probe Microanalyzer results show that small amount of B atoms are dissolved into B2 matrix and the other B atoms result in the formation of FCC phase. The addition of B content leads to transformation of microstructure from pure B2 phase to “B2 phase + particle FCC structure” and then to “B2 phase + eutectic structure”. Eutectic structure consists of FCC1 phase and FCC2 phase. FCC1 phase is rich in Co and Ni and FCC2 phase is rich in B, Fe and Co. With the increase of B content, grain size of B2 phase firstly reduce and then increase. By increasing the B content from 0 to 0.2, fracture strength and plastic strain increase from 850 MPa to 2293 MPa and 0.07 to 0.27 respectively. The increase of yield strength is due to the solid solution strengthening and fine grain strengthening of boron atom. While, the increase of plasticity is due to the formation of FCC eutectic structure.

The effect of boron content on the microstructure and mechanical properties of Fe50-XMn30Co10Cr10BX (x = 0, 0.3, 0.6 and 1.7 wt%) multi-component alloys prepared by arc-melting

High and Medium- Entropy Alloys (HEAs and MEAs) are a novel type of materials, which due to the reduction in configurational entropy, can offer an excellent combination of properties, such as, high strength, high ductility and moderate hardness. During the study, four alloys based on Fe50-XMn30Co10Cr10BX system (x = 0, 0.3, 0.6 and 1.7 wt%) were manufactured by arc melting. The microstructure of the materials was analyzed by optical microscopy, scanning electron microscopy, and X-ray diffraction. The Vickers microhardness of these alloys were also measured. Detailed characterization revealed the formation of a dual-phase matrix (fcc + hcp) due to the reduction in the stability of the fcc phase that led to a thermal induced partial martensitic transformation into a ε-hcp phase. The addition of boron promoted the formation of M2B-type borides (M = Cr, Fe), whose content increased with the addition of B. Changes in the phase composition, specifically the decrease of the hcp phase, were mainly due to the loss of manganese content. The microstrain analysis showed the absence of residual stresses in the crystal lattice due to a decrease in the dislocation’s density after the martensitic transformation. When boron content was brought from 0 wt% to 1.7 wt%, the microhardness of the material increased from 296HV to 452 HV, which is comparable to the microhardness of high-manganese steel. Finally, the thermodynamic parameter Φ was calculated using a phase prediction package AlloyASAP, allowing to establish that boron addition to Fe50Mn30Co10Cr10 originated medium-entropy alloys (Φ < 1), while the absence of boron give a high-entropy alloy (Φ > 1).

Effect of boron addition on microstructure, mechanical properties and oxidation resistance of TaC ceramics

TaC ceramics with 0.03–0.60 wt% of boron additions were prepared by hot pressing at 2100 °C for 1 h under a pressure of 40 MPa. Effects of boron content on densification, phase composition, microstructure, mechanical properties and oxidation resistance of the TaC ceramics were investigated. When the boron content was 0.12 wt% and above, full density was obtained due to reactions between boron and oxygen impurity at presence of TaC. Minor phases of TaB2 and C were formed in the 0.24 and 0.60 wt% B compositions after gas-out of the oxygen impurity. Microstructure of the TaC ceramics was refined with increasing in boron content. The TaC ceramic with 0.24 wt% of boron showed the best mechanical properties with a Vickers hardness, flexural strength and fracture toughness of 17.7 GPa, 534 MPa and 4.6 MPa m1/2, respectively. When more boron was added, interfacial bonding of the TaC grains was strengthened causing a decrease in fracture toughness. Oxidation resistance of the TaC ceramics increased with boron content. Particularly, the 0.60 wt% B composition showed a weight gain of 0.0018 g/cm2 after oxidization at 800 °C in air for 3 h.

The Effect of Boron Content on Wetting Kinetics in Si-B Alloy/h-BN System

In this work, the effect of boron content on the high-temperature wetting behavior in the Si-B alloy/h-BN systems was experimentally examined. For this reason, hypoeutectic, eutectic and hypereutectic Si-B alloys (Si-1B, Si-3.2B and Si-5.7B wt.%, respectively) were produced by electric arc melting method and then subjected to sessile drop/contact heating experiments with polycrystalline h-BN substrates, at temperatures up to 1750 °C. Similar to pure Si/h-BN system, wetting kinetics curves calculated on a basis of in situ recorded drop/substrate images point toward non-wetting behavior of all selected Si-B alloy/h-BN couples. The highest contact angle values of ~ 150° were obtained for hypoeutectic and eutectic Si-B alloys in the whole examined temperature range.

Effect of boron on the efficiency of MoCo catalysts supported on alumina for the hydrodesulfurization of liquid fuels

Abstract The effect of boron content on hydrodesulphurization (HDS) activity was investigated under different optimized conditions. γ-Al2O3 was loaded with MoCo and then doped with boron. The obtained materials, i.e. AlMoCoB0%, AlMoCoB2%, and AlMoCoB5% were characterized by N2-physisorption, X-ray diffraction, temperature programmed analysis by reduction and desorption, Fourier-transform infrared spectroscopy, a scanning electron microscopy, transmission electron microscopy, and thermogravimetric analysis. The catalytic activity of the prepared catalysts was evaluated for the HDS of dibenzothiophene (DBT) using a Parr batch reactor at T = 300 °C and under 50 bar hydrogen partial pressure. The textural properties of the prepared catalysts were enhanced by introducing the boron. For example, the BET surface area of AlMoCoB5% was 206 m2/g which is higher than that of both AlMoCoB0% and AlMoCoB2%. The acidity and dispersion AlMoCoB5% were 0.77 and 2.46 (mmol/g), respectively, which increase its HDS activity. The boron enhanced the particle dispersion, leading to an improvement in the catalytic activity of the MoCo catalysts in the elimination of sulfur content. Experimental factors (such as temperature, pressure, the dosage of the catalysts and contact time) were investigated and optimized using a central composite design. The results revealed that the HDS was improved by increasing the temperature, pressure, and catalyst dosage. The optimum contact time was found to be 6 h with a dosage of 0.6 g. The experimental results indicated that AlMoCoB5% has the highest HDS activity, achieving more than 98% of sulfur removal, which is below the allowed sulfur level. The excellent catalytic activity of the AlMoCoB5% catalyst in the HDS of DBT is particularly useful for the ultradeep HDS of fuels.