Boron Addition Research Articles

Experimental and Simulation Study on Shielding Performance of Developed Hydrogenous Composites

Space radiation has been well-known as the main health hazard to crews involved in manned space explorations. Two kinds of hydrogenous-rich composites are developed through compressing molding under high-temperature processing techniques for shielding space radiation. Beams of 80~400 MeV/n 12 C of the Heavy Ion Research Facility in Lanzhou are used to test the shielding properties of the new composites. Experimental results show that the composite with more hydrogen content has higher shielding ability for 80 and 400 MeV/n 12 C particles. Meanwhile, the addition of boron has no obvious effect on improving the shielding performance of the composite. Monte Carlo radiation transport codes were used to assess the shielding performance of composite in real space radiation. The simulation results show that hydrogenous-rich composite has significant advantage in space radiation shielding compared with traditional aluminum.

Improving the Soft Magnetic Properties of Binder Jet Printed Iron-Silicon Alloy Through Boron Addition

Improving the Soft Magnetic Properties of Binder Jet Printed Iron-Silicon Alloy Through Boron Addition

Influence of V2O5 and B2O3 addition on the sintering behaviour and physical properties of ZnO ceramics

The effect of V2O5 and B2O3 additions on sintering behaviour and physical properties of ZnO ceramics was investigated. XRD studies revealed ZnO as main phase with a hexagonal wurtzite-type structure. The V2O5 addition is the reason for an increase in grain size and some grains of oblong shape morphology in the ZnO ceramics. The dual addition of V2O5-B2O3 improved the liquid-assisted sintering of ZnO ceramics and resulted in further increase in grain size with more uniform grain growth. The reduction of sintering temperature to 900?C for ZnO ceramics was observed with the dual addition of V2O5 and B2O3. The room temperature PL spectra of the Z (ZnO), ZV (ZnO with 0.5mol% V2O5) and ZVB (ZnO with 0.5mol% V2O5 and 0.5mol% B2O3) ceramics revealed broad visible emission band because of impurities and defects in ZnO ceramics caused by oxygen vacancies due to vanadium and boron additions, as well as zinc interstitials. This emission band between 450-750 nm includes the entire visible region from blue to red.

Role of Boron Addition in Tuning Microstructure and Mechanical Properties of Alnbtizr Based High-Entropy Alloy

Role of Boron Addition in Tuning Microstructure and Mechanical Properties of Alnbtizr Based High-Entropy Alloy

Effect of boron addition on the gear fatigue strength of Fe-Ni-Mo-B-C sintered alloys

Effect of boron addition on the gear fatigue strength of Fe-Ni-Mo-B-C sintered alloys

The Innovative Role of Boron Addition to D-D Spherical Fuel Pellet and Simultaneous Radiation of Deuteron Beam in Fast Ignition to Enhance Fusion Energy Gain

The Innovative Role of Boron Addition to D-D Spherical Fuel Pellet and Simultaneous Radiation of Deuteron Beam in Fast Ignition to Enhance Fusion Energy Gain

Effects of Boron Application and Gamma Ray Irradiation On Yield of Sugar Beet (Beta Vulgaris L.) Grown in Sandy Soil

Effects of boron as an essential nutrient for sugar beet along with gamma irradiation was traced under field conditions. Data demonstrated that the fresh and dry root yields of sugar beet significantly increased with the increase either gamma dose or boron levels comparing to the non-irradiated and born-untreated plants. It seems that root dry weight tended to increase gradually with increasing gamma dose 0 to 100 Gy, then tended to decrease with 200 Gy dose but it still increased with gradual increases of boron levels. In this regard, the best value of root dry weight was achieved with 100 Gy dose interacted with 2.40 kg/ ha of boron addition. On the other hand, plants exposed to 50 Gy and treated with 2.40 kg/ ha reflected the highest shoot dry matter yield compared to other treatments. Relatively, this treatment increased shoot dry weight by about one fold, two folds and near to two folds for the same sequence. Behavior of NPK uptake by shoots has the same trend. Plants irradiated with 100 Gy together with 2.40 kg boric acid ha-1 yielded the highest total soluble solids (TSS%) and produced the best per cent of sucrose. Bangladesh J. Bot. 50(4): 1041-1049, 2021 (December)

Effects of boron on the microstructure and impact toughness of weathering steel weld metals and existing form of boron

In this study, the effects of various boron contents on the microstructure, impact toughness, and fracture surface of the weathering steel weld metals were firstly investigated. Secondly, the existence form and distribution of the boron element were also studied. Results indicated with the increase of boron content, the microstructure gradually changes from block ferrite to granular bainite, the amount of boron-containing second phases obviously increases, and the low temperature impact toughness first increases and then decreases. The weld metal with 0.0042% boron content has the best low temperature impact toughness. Compared to the weld metals with boron free and boron content of 0.0087%, the ductile brittle transition temperature of the weld metal with boron content of 0.0042% is reduced by 29 °C and 25 °C respectively. Due to the transformation of microstructure and the increase of second phases, the microhardness presents an increasing trend. By means of Secondary Ion Mass Sectrometry (SIMS), the distribution and existing forms of boron are accurately characterized. It is found that boron is mainly concentrated on the original austenite grain boundary in the form of boron oxide, and a very small amount of boron exists in the form of boron carbide. Therefore, the appropriate amount of boron can significantly improve the low-temperature impact toughness of the weathering steel weld metal. The optimal boron content in this study is 0.0042%. Excessive or insufficient boron addition leads to the reduction of low-temperature impact toughness.

Analysis of the effect of boron addition on steels for forged components

Following the high cost of Mo and other alloying elements, many attempts are being carried out aimed to improve the hardenability of high thickness forged components without increasing their price. In this work the effect of B is examined on laboratory scale. In particular, two ingots have been cast in a pilot plant, with boron addiction. Boron as been added in a protected steel chemical composition, so to be effective in terms of hardenability. Materials were then hot rolled and cooled favoring the formation of a microstructure typical of that of forged components. Results on the material are compared to that of a standard steel in terms of hardenability. Copyright © 2018 VBRI Press.

Modelling the tribological response in dry sliding of boron modified as-cast Ti6Al4V on hardened steel

Tribological characteristics of boron modified as-cast Ti6Al4V alloys are not very well known, but these alloys enjoy improved as-cast mechanical properties and favourable manufacturing economy. Experimental results are reported here for the effects of sliding speed and normal load on the wear rate and the coefficient of friction in dry sliding of these alloys on hardened EN 31 steel. Alloys having 0%, 0.30%, and 0.55% boron by weight were tested. A full factorial experiment assessed the effects of boron content, speed, and load on wear and friction. Interactions between speed and load were found to be statistically significant in influencing the wear rate and the coefficient of friction. Regression models are developed to predict the wear rate and coefficient of friction responses. The developed contour plots can assist designers in choosing operating conditions when selecting these alloys even if the wear mechanisms are unknown. Evidence shows that the wear resistance of Ti6Al4V can be improved by boron addition, and wear regimes are sensitive to boron content.

Characterization and Analysis of Nanocrystalline Soft Magnetic Alloys: Fe Based

Soft magnetic nanocrystalline alloys have been widely analysed and studied during the past years. However, optimisation of specific chemical compositions is still being developed. The applicability of these soft nanocrystalline alloys depends mainly on the presence of the desired nanocrystalline phases within the alloy. In this study, the analysed alloys are manufactured by mechanical alloying. The analyses performed on the samples include a microstructural analysis, a thermal analysis, and a complementary functional analysis in the form of the thermomagnetic response of some samples. Regarding Fe-based alloys, thermal stability for samples containing B was higher than those containing P (crystal growth peaks in the range between 895–905 K and 775–800 K respectively). The higher magnetization of saturation, Ms, was found in Fe–Mn alloys, whereas the addition of boron provoked a decrease of Ms and the nanocrystals size.

Transplanting and the addition of boron in sweet corn (Zea mays L. group saccharate) production

Introduction. Low seedbed temperatures at the planting and the direct sowing method can reduce the sweet corn germination. Transplanting may offer optimum environmental conditions for seed germination, early crop maturity, and increase sweet corn (Zea mays L. group saccharata) productivity. Boron deficiency depresses sweet corn yield through male sterility. Objective. To evaluate the effect of transplanting and the addition of boron in sweet corn production. Materials and methods. A field experiment was conducted from March 19 to June 20, 2020 at the Research Station of Horticulture Department and Landscape Gardening Architecture, University of Diyala, Baqubah, Iraq. Direct sowing and transplanting, and foliar application of boron at 0, 50, or 75 mg L-1 was evaluated to determine effects on the yield, the yield components, and water use efficiency of sweet corn cultivars: Roi Soleal, Seker misir, and Succar. Results. The cv. Seker Misir matured faster (57.5 days), had wider ears (4.53 cm), more kernel rows (16.0), the highest kernel yield (6.00 t ha-1), and a higher water use efficiency (WUE) (2.85 kg m-3). The cv. Succar had the longest ears (18.48 cm) and the heaviest fresh ears (251 g). Transplanting hastened the time to maturity (54.18 days), and produced the longest ears (17.91 cm), widest ears (4.52 cm), most kernel rows (15.96), heaviest fresh ears (229 g), the highest kernel yield (5.56 t ha-1), and the highest WUE (2.64 kg m-3). The 50 mg L-1 fertilizer treatment produced the longest ears (17.61 cm), widest ears (4.58 cm), more kernel rows (16.61), the highest kernel yield (5.64 t ha-1), and the highest WUE (2.68 kg m-3). The least time to maturity (57.72 days) and heaviest fresh ears (232 g) occurred with 75 mg L-1 of boron fertilizer. Conclusion. The use of 50 mg L-1 boron, as a foliar fertilizer, appears to be, next to the transplanting method, suitable for the cultivation of sweet corn plants to increase productivity and WUE.

Microstructural and mechanical characterization of cobalt-based superalloys with the addition of boron and zirconium

Microstructural and mechanical characterization of cobalt-based superalloys with the addition of boron and zirconium

Eucalyptus grandis Response to Calcium Fertilization in Colombia

Abstract Calcium (Ca) is a critical plant nutrient typically applied at the time of planting in intensive Eucalyptus plantations in South America. At two sites in Colombia, we examined (1) calcium source by comparing growth after application of 100 kg ha−1 elemental Ca as lime or as pelletized highly reactive calcium fertilizer (HRCF) compared to a no application control, and (2) Ca rate by applying 0, 100, 200, and 400 kg ha−1 elemental Ca as HRCF with the addition of nitrogen, phosphorus, potassium, sulfur, and boron (NPKSB). We assessed height, diameter, and volume after 12 and 24 months. There were no growth differences from Ca source at the 100 kg ha−1 rate. We found increased volume after 24 months at the “Popayan” site with 200 and 400 kg ha−1 Ca HRCF+NPKSB treatments (112 and 113 m3 ha−1, respectively) compared to control (92 m3 ha−1), a 22% increase. In contrast, volume did not differ after 24 months at the “Darien” site, ranging from 114 m3 ha−1 in the 0 kg ha−1 Ca HRCF+NPKSB treatment to 98 m3 ha−1 in the control. Differences in response are likely due to soil characteristics, such as organic matter, emphasizing the importance of identifying site-specific nutrient deficiencies.

The radiation properties of burning clouds of metal dust. 3. Modification of the emission spectrum

In this work we studied the emission spectra of the combustion products of low-volume dust clouds (V = 5 L) from aluminum (ASD-4), as well as clouds from mixed compositions of aluminum with inorganic powdery oxidizing agents (NaNO3, NaCl, Na2CO3·10H2O, Sr(NO3)2, Ba(NO3)2, KNO3, CuSO4, CuSO4·10H2O) and combustible (B, AlB2, Cu). This article discusses the possibilities of purposeful modification of the emission spectrum of the base composition using various inert and optically active dispersed additives that shift the maximum of the emission spectrum of the fuel composition to the region of longer waves or cause a local change in the emission spectrum in the corresponding spectral regions.
 In the course of the experiments, it was revealed that the introduction of additives into the basic composition of dispersed fuel does not significantly change the dynamic characteristics of the suspension. However, the additives lead to a decrease in temperature (by about 100–200°K in the presence of an additive up to 25% by weight) and to a corresponding shift in the maximum of the radiation spectrum.
 The possibility of a significant local modification of the spectrum in the yellow region with the help of inorganic additives to the fuel of sodium salts with a low decomposition temperature (additives Na2CO3·10H2O) was shown experimentally. Boron additives and boron compounds (B, AlB2) leads to a significant increase in the luminosity of the flame in the green region of the spectrum with a maximum radiation in the range Δλ = 530 ÷ 580 nm. The article presents the lighting characteristics (luminous intensity, light sum) of large clouds (V ≥ 10 m3) of mixed compositions based on PAP-2 aluminum powder.
 It was found that the introduction of inorganic additives to the base fuel does not lead to a noticeable change in the lighting characteristics, but somewhat increases the time of the cloud glow both in the visible and infrared parts of the spectrum.

Boron-Modified Mesoporous ZSM-5 for the Conversion of Pyrolysis Vapors from LDPE and Mixed Polyolefins: Maximizing the C2–C4 Olefin Yield with Minimal Carbon Footprint

Recovering monomers from polyolefins is challenging due to their chemical inertness. Chemical recycling via pyrolysis produces a complex liquid requiring subsequent upgrading and further processing. In the presented work, low-density polyethylene and postconsumer mixed polyolefin (MPO) waste were pyrolyzed at 550 °C and the vapors were passed over a catalyst to maximize the production of monomers, that is, light olefins and aromatics, which could produce new polymers in a circular approach. Hierarchical HZSM-5 zeolites containing both micro- and mesopores and their boron-modified versions with medium and high Si/Al ratios were studied and thoroughly characterized. The effect of catalyst temperature (550–700 °C), catalyst/feed ratio, steam treatment, and catalyst deactivation by coking was investigated using a tandem micropyrolyzer coupled to comprehensive two-dimensional gas chromatography and flame ionization detection/time-of-flight mass spectrometry detectors, allowing a detailed identification and quantification of the products. All catalysts effectively narrowed the product distribution with high selectivity toward C2–C4 olefins, monoaromatics, and C5–C11 aliphatics. HZSM-5 zeolite catalysts with a medium Si/Al ratio showed a higher monomer recovery (∼90%) than high Si/Al (∼80%), which has a higher selectivity to C5–C11 aliphatics. Importantly, the product yield distribution from MPO closely resembled low-density polyethylene. The addition of boron to the zeolite reduced the aromatization activity. Similarly, at comparable conversion levels, mild steam treatment of the catalyst lowered the selectivity to aromatics and increased the recovery of C2–C4 olefins. Hierarchical HZSM-5 zeolite showed improved tolerance against deactivation by coking compared to conventional HZSM-5, demonstrating the potential of boron-modified hierarchical HZSM-5 zeolite to recover monomers from polyolefin waste at high selectivity.

The Effect of Boron on the Microstructure and Properties of Refractory Metal Intermetallic Composites (RM(Nb)ICs) Based on Nb-24Ti-xSi (x = 16, 17 or 18 at.%) with Additions of Al, Cr or Mo.

This paper is about metallic ultra-high temperature materials, in particular, refractory metal intermetallic composites based on Nb, i.e., RM(Nb)ICs, with the addition of boron, which are compared with refractory metal high entropy alloys (RHEAs) or refractory metal complex concentrated alloys (RCCAs). We studied the effect of B addition on the density, macrosegregation, microstructure, hardness and oxidation of four RM(Nb)IC alloys, namely the alloys TT2, TT3, TT4 and TT8 with nominal compositions (at.%) Nb-24Ti-16Si-5Cr-7B, Nb-24Ti-16Si-5Al-7B, Nb-24Ti-18Si-5Al-5Cr-8B and Nb-24Ti-17Si-3.5Al-5Cr-6B-2Mo, respectively. The alloys made it possible to compare the effect of B addition on density, hardness or oxidation with that of Ge or Sn addition. The alloys were made using arc melting and their microstructures were characterised in the as cast and heat-treated conditions. The B macrosegregation was highest in TT8. The macrosegregation of Si or Ti increased with the addition of B and was lowest in TT8. The alloy TT8 had the lowest density of 6.41 g/cm3 and the highest specific strength at room temperature, which was also higher than that of RCCAs and RHEAs. The Nbss and T2 silicide were stable in the alloys TT2 and TT3, whereas in TT4 and TT8 the stable phases were the Nbss and the T2 and D88 silicides. Compared with the Ge or Sn addition in the same reference alloy, the B and Ge addition was the least and most effective at 800 °C (i.e., in the pest regime), when no other RM was present in the alloy. Like Ge or Sn, the B addition in TT2, TT3 and TT4 did not suppress scale spallation at 1200 °C. Only the alloy TT8 did not pest and its scales did not spall off at 800 and 1200 °C. The macrosegregation of Si and Ti, the chemical composition of Nbss and T2, the microhardness of Nbss and the hardness of alloys, and the oxidation of the alloys at 800 and 1200 °C were also viewed from the perspective of the alloy design methodology NICE and relationships with the alloy or phase parameters VEC, δ and Δχ. The trends of these parameters and the location of alloys and phases in parameter maps were found to be in agreement with NICE.

Effects of Grain Boundary Geometry and Boron Addition on the Local Mechanical Behavior of Interstitial-Free (IF) Steels

Effects of Grain Boundary Geometry and Boron Addition on the Local Mechanical Behavior of Interstitial-Free (IF) Steels

Effect of boron segregation on bainite nucleation during isothermal transformation

The effects of boron segregation and austenite grain size on the bainitic isothermal transformation of a high-strength steel were studied independently. Dilatometry, microstructural observations and previous atom probe tomography analyses showed that bainitic transformation rate decreases with increasing boron excess at austenite grain boundaries. We also found that boron segregation causes an unexpected grain size effect: large austenite grains transform faster than small ones. A kinetic model assuming slow nucleation at austenite triple junctions and rapid growth of bainitic nuclei successfully described our experimental data. These results confirm that bainite nucleation is inhibited by segregated boron at grain boundaries. On this basis, austenitic grain size could be optimized to make the most of boron addition in advanced high-strength steels.

Boron‐Mediated Grain Boundary Engineering Enables Simultaneous Improvement of Thermoelectric and Mechanical Properties in N‐Type Bi2Te3

Powder metallurgy introduces small structures of high-density grain boundaries into Bi2 Te3 -based alloys, which promises to enhance their mechanical and thermoelectric performance. However, due to the strong donor-like effect induced by the increased surface, Te vacancies form in the powder-metallurgy process. Hence, the as-sintered n-type Bi2 Te3 -based alloys show a lower figure of merit (ZT) value than their p-type counterparts and the commercial zone-melted (ZM) ingots. Here, boron is added to one-step-sintered n-type Bi2 Te3 -based alloys to inhibit grain growth and to suppress the donor-like effect, simultaneously improving the mechanical and thermoelectric (TE) performance. Due to the alleviated donor-like effect and the carrier mobility maintained in our n-type Bi2 Te2.7 Se0.3 alloys upon the addition of boron, the maximum and average ZT values within 298-473 K can be enhanced to 1.03 and 0.91, respectively, which are even slightly higher than that of n-type ZM ingots. Moreover, the addition of boron greatly improves the mechanical strength such as Vickers hardness and compressive strength due to the synergetic effects of Hall-Petch grain-boundary strengthening and boron dispersion strengthening. This facile and cost-effective grain boundary engineering by adding boron facilitates the practical application of Bi2 Te3 -based alloys and can also be popularized in other thermoelectric materials.