Addition Of BN Research Articles

Flexible silane‐functionalized boron nitride filled polymer composite with high thermal conductivity and electrical insulation

AbstractBoron nitride (BN) has excellent thermal conductivity (TC), however, it exhibits high surface energy, strong chemical inertness, poor interface compatibility with polymer matrices, and difficulty in even dispersion within‐polymer matrix, preventive effective construction of TC pathways. Four kinds of modified boron nitride/polyurethane composites (BTPUC) were prepared by different silane‐functionalized BN with polyurethane (TPU). Among them, 3‐trimethoxysilylpropylmethacrylate (TMSPMA)‐functionalized BN demonstrated better interface compatibility with TPU, significantly improving the mechanical properties and TC of the composites compared to the other three functionalized BN addition. The BN@TMSPMA/PU exhibited good TC and mechanical properties, with a TC of 0.865 W/mK, a tensile stress and a tensile strain of 9.65 ± 1.40 MPa and 759.88 ± 67.93%, respectively. It also showed good electrical insulation properties and mechanical durability. Therefore, the as‐prepared BN@TMSPMA/PU have broad prospects as flexible thermal‐management materials.Highlights The composites are constructed by TMSPMA‐modified BN and polyurethane by NIPS. The composites show good mechanical properties and cyclic failure resistance. The composites exhibit good thermal conductivity and electrical insulation.

Additive manufacturing of novel aluminium matrix composites with enhanced strength and processability via boron nitride functionalization

The present work systematically investigates the effects of BN nanopowder functionalization on the processability, microstructure and tensile response of the custom Powder Bed Fusion Laser Beam (PBF-LB) Al alloy ‘AMALLOY3D’. The results show that a minor addition of BN (0.3% by weight) not only produces near fully dense parts (99.91%), but is also paired with improved flowability, enhancing the overall processability. Electron backscatter diffraction (EBSD) analysis revealed the transformation to a fully equiaxed grain structure in the BN-functionalized material, resulting in a 40% increase in yield strength. Energy dispersive spectroscopy using a scanning transmission electron microscope (STEM-EDS) was employed to reveal the intricate secondary phases’ arrangements. These observations coupled with the help of the CALPHAD approach led to the reconstruction of the solidification history of AMALLOY3D and the BN-functionalized material. The present study unravels the complex dynamics leading to the columnar-to-equiaxed transition in BN-reinforced AMCs, proving that such unique microstructures and exceptional tensile properties can be achieved without compromising PBF-LB processability.

Densification, microstructure, and wear properties of TiB2-TiC-GNP and TiB2-TiC-BN composites

In this study, TiB2–TiC, TiB2–TiC-GNP, and TiB2-TiC-BN composites were produced via spark plasma sintering (SPS). The densification and sintering behavior, phase and Raman spectroscopy analyses, microstructural properties, Vickers microhardness, and wear behavior of the binary and ternary composites were investigated. The addition of various amounts of TiC to TiB2 resulted in nearly complete densification. The TiB2–TiC-GNP specimens exhibited a relative density of more than 99 %; in contrast, the addition of BN did not contribute to the densification. The Vickers hardness of the GNP-added composites was ∼25 GPa, whereas hBN addition to the matrix decreased the hardness to ∼22 GPa (∼9 % decrease). According to the wear test, the addition of GNPs did not result in a significant change in the TiB2–TiC matrix; however, the addition of hBN increased the specific wear rate of the matrix by ∼100 %. The GNPs did not have a negative effect on the densification, microstructural, or mechanical properties, such as the Vickers hardness and wear resistance. Hence, they were determined to be a more suitable sintering aid for matrix composition than hBN.

Surface topography and surface morphology of graphene nanocomposite by FESEM, EDX and AFM analysis

The analyzed nanocomposites of this research have been fabricated by the sintering method, where different percentages of boron nitride, zinc oxide, aluminum oxide and titanium oxide have reinforced graphene. The percentages of additives were varied from 0 % to 5 %. An investigation of nanostructural observation, phase identification and structural analysis of graphene nanoparticles has been performed using Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray (EDX) analysis and X-Ray Diffraction (XRD) analysis. The morphology of the synthesized materials was investigated by examining the FESEM pictures at different magnifications. The micrographs depict the hetero-materials' amalgamation, resulting in the formation of compacted particles that collectively exhibit a prominent bulbous morphology. The size and shape of different particles in the nanocomposites are visible from the FESEM images. The assays conducted by EDX have verified the presence of the necessary components, exhibiting a high degree of purity. Further insights about the nanocomposites have been obtained from Atomic Force Microscopy (AFM) analysis. AFM analysis revealed the surface roughness, which increased to 11.9 from 4.4 µm due to the addition of BN. The crystalline structure has been confirmed from the XRD analysis.

Successful synthesis of proton-conducting high-entropy (La0.2Nd0.2Ho0.2Lu0.2Y0.2)2ZrO5 ceramics

Using mechanical activation of an oxide mixture containing 0.2 wt% hexagonal boron nitride, followed by high-temperature firing (1400–1500 °C), we prepared single-phase (La0.2Nd0.2Ho0.2Lu0.2Y0.2)2ZrO5 ceramic, a high-entropy oxide (HEO) analog of Gd2ZrO5, whereas we failed to obtain single-phase Gd2ZrO5 under similar conditions: the material consisted of two phases, with the fluorite and bixbyite structures, like in the case of conventional synthesis or coprecipitation in previous work. Thus, the use of the HEOs allowed us to obtain a phase-pure compound with the fluorite structure at a markedly lower synthesis temperature. An important role was played by 0.2 wt% hyperstoichiometric hexagonal BN additions, which ensured considerable amorphization of the starting oxides. The start powders and resulting ceramics were studied by X-ray diffraction, SEM analyses and conductivity was measured by impedance spectroscopy method in dry and wet air.The highest proton conductivity, ∼2.5 × 10−5 S/cm at 630 °C, was offered by the (La0.2Nd0.2Ho0.2Lu0.2Y0.2)2ZrO5 HEO ceramic. The use of HEO analogs of various compounds can be helpful for not only assessing thermodynamic properties of ceramics (reduction in synthesis and polymorphic transformation temperatures), but also preparing proton conductors when it is necessary to enhance hydrating properties of the cation sublattice.

Synthesis and characteristic analysis of an inorganic composite phase change materials for medium-temperature thermal storage

Composite phase change materials (CPCM) synthesized using inorganic salt (Na2HPO4·12H2O), lime fruit peel biochar (activated), and boron nitride have been explored as a solution for the medium-temperature thermal energy storage systems in this work. The activated biochar and BN concentrations were varied, and the effects of the activated biochar and BN on the thermal properties, chemical, and thermal stability of the phase change materials (PCM) were studied. XRD and FTIR studies confirmed the chemical stability of the synthesized CPCM samples. Leak test results revealed that the addition of biochar and BN has improved the shape stability. TGA studies revealed the superior thermal stability of the CPCM samples. Composite PCM with 2 g of activated biochar and 0.5 g of BN has exhibited better thermal properties with a latent heat of 121.33 J/g, encapsulation efficiency of 55.9%, and thermal energy storage capacity of 98.2% compared to the pure PCM.

E-waste CRT panel glass reinforced magnesium composite processed through powder metallurgy: fabrication and mechanical performance evaluation

Cathode Ray Tube (CRT) panel glass with higher silica content has a potential to be used as reinforcement material in magnesium matrix composites. The present study aims to formulate a wear resistant magnesium hybrid composite by reinforcing silica rich E-waste CRT panel glass powder (0, 10 and 20 wt. %) and boron nitride (0, 2 and 4 wt. %) solid lubricant processed through powder metallurgy route. Composition of the CRT panel glass powder is identified through EDS and XRD analysis is performed for both base material and reinforcements. The developed green MMC shows increased hardness (∼53 %), porosity (∼7 %) and density (∼7 %) with respect to addition of CRT reinforcement. Porosity of hybrid composite increased vastly to 9.2 % when the CRT and BN content are increased to 20 % and 4 % respectively. A slight increment in (10 %) hardness is observed for 2 % addition of BN with Mg and Mg/CRT composite whereas hardness of the Mg and Mg/CRT MMC decreases with further addition of BN. The wear resistance of the composite enhanced with raise in CRT and BN content whereas the co efficient of friction decreases with increases in BN percentage. Corrosion behaviour of Mg is also analysed and found enhanced with reinforcement addition. It is identified from the results that the addition of CRT% up to 10 % yields significant results whereas further increase in CRT % to 20 provides only minor enhancements in properties. Further, it is suggested to restrict the addition of BN to 2 %.

The effect of hexagonal boron nitride nanopowders addition on the mechanical behaviors of basalt fabric reinforced composites

Purpose The purpose of this paper is to investigate the effect of doping element on the structural, thermal properties, mechanical performance and the failure mechanism of hexagonal nano boron nitride (h-BN)-reinforced basalt fabric (BF)/epoxy composites produced by hand lay-up and vacuum bagging technique. h-BN particles doped to composite materials increased the tensile, bending and impact strength of the composite at certain rates while 1 Wt. % h- BN addition shows the highest tensile and flexural strength. Design/methodology/approach The epoxy resin was doped with h-BN nanopowder at the certain rates (0, 1, 2 and 4 Wt.%) and the epoxy: hardener ratios used in the study were selected as 80%: 20% by weight. Then, with the aid of a roller by hand lay-up method, a mixture of epoxy + hardeners containing nanoparticles and nanoparticle-free were fed onto BFs, 12 layers of each dimension 30 cm × 30 cm. The surplus epoxy resin was moved away from the composite sheets using the vacuum bagging process and left to cure at room temperature for 24 h. ASTM D3039 for tensile, D7264 for three-point bending and D256 for Izod impact test were performed for the mechanical tests. After the tensile test, the morphologies of the fracture surface were examined with a stereomicroscope and various failure mechanisms are highlighted. Findings In this study, a series of basalt/epoxy composites with h-BN nanopowders have been prepared to identify the effect of filler ratio on mechanical properties. It has been known from the results of mechanical experiments that the addition of h-BN improves the mechanical performance of materials at a certain rate. The tensile and flexural strengths of h-BN doped composites, increase for concentrations of 1 Wt.% h-BN, but decrease with the increasing content of it. The basalt/epoxy resin composite with higher mechanical properties could be a potential material in the automotive and aerospace industries. Originality/value The aim of this study is to contribute to literature within the context of this new combination of composites and their mechanical properties, failure mechanisms. It presents detailed characterization of each composite by using X-ray differaction (XRD), differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy.

Effect of BN addition on mechanical and electrical properties of oxidative sintered porous Si3N4-BN composites

In order to explore the effects of BN addition on the mechanical and electrical properties of oxidative sintered Si3N4-BN composites, Si3N4-BN composites with BN powder dosage of 0-40 wt% are prepared by molding technology, and the effects of different BN contents on the phase, morphology, bulk density, porosity, flexural strength at room temperature, dielectric constant and dielectr loss of the composite system are studied. With the increase of BN content, at different temperatures, the oxidation product B2O3 of BN and the oxidation product SiO2 of Si3N4 firstly react on the surface to form B2O3–SiO2 glass phase, which densify the surface and affects the oxidation degree of internal grains. At the same time, a small amount of B2O3 escaping from the surface, so that the open pores of the composites decrease firstly and then increase slightly, and the dielectric constant increases firstly and then decreases. The results show that when the amount of BN micronized powder is 10 wt%, the oxidation sintered Si3N4-BN composite material at 1500 °C have pores that retain the sheet structure of boron nitride, and the amorphous material flows to fill the pores, so it have high volume density (1.85 g/cm3), low porosity (apparent porosity 6.37%), and high mechanical properties (flexural strength 127.86Mpa), higher dielectric constant (3.94) and lower dielectr loss (4.0 × 10−4).

The tribocorrosion resistance of TiN+TiB /TC4 composite coatings and the synergistic strengthening effects of multi-level reinforcements

The Ti-based composite coating of TiN + TiB /TC4 is successfully fabricated by laser cladding. The results show that the addition of BN promotes the in-situ formation of an elliptic TiN phase at the micron level and fibrous TiB phase at the nanometer level, forming a new structure of the hard TiN surrounded and pinned by coherent TiB. No obvious plastic deformation occurs with the increase of TiN and TiB phases, and the dense TiO2-MoO3 oxide film forms during tribocorrosion. The tribocorrosion rate is much reduced and drops to the lowest rate of 246.93 ± 14 µm/yr.

Poly(lactic acid) based Pearl Layer Moistureproof Membrane for Flexible Laminated Packaging.

The development of bio-based polymer materials, such as polylactic acid (PLA) -based polymers, is an effective strategy to reduce dependence on petrochemical-based polymers. However, the preparation of bio-based polymers with high barrier properties is a major challenge. To overcome this challenge, a nacreous layer structure with a ' brick and mud ' pattern is mimicked to improve the overall performance of the material. In this paper, Poly (L -lactic acid) (PLLA) and Polypropylene Glycol (PPG) was combined to prepare bio-based polyurethane (PU-PLLA), which is used as the slurry structure of nacreous layer. The bio-based biomimetic composite membrane (PU-PLLA/BN) is then obtained by adding boron nitride (BN, brick structure of pearl layer) to it. The water vapor permeability test results show that the permeability of PU-PLLA material can be reduced by more than 50% by 5 wt.% BN, which is because the addition of BN can increase the length and tortuosity of the gas molecular diffusion path in the composite. Therefore, this pearl-inspired PU-PLLA/BN film has excellent moisture resistance, which opens up a broad road for the practical application of PLLA in flexible laminated packaging.

Effect of additives on selective laser sintering of silicon carbide

Silicon carbide-based composite ceramic is manufactured by one-stage selective laser sintering. The effect of the sintering parameters and raw materials on the sinterability of SiC based composite is studied. The optimization of the parameters is carried out. In a single stage of selective laser sintering, it is possible to achieve 87% relative density. The influence of particle size of feedstock, as well as BN and Y2O3 additives on the sinterability, mechanical and thermal properties of the samples are studied.For composites that contain 10% BN, the thermal expansion coefficient increases from room temperature to 900°C. The electrical resistivity decreases both in the room and at cryogenic temperature (−200°C). The thermal conductivity and mechanical properties of BN-containing samples decrease as well. Yttrium oxide-containing samples show higher thermal conductivity and electrical resistivity than boron nitride-containing samples.

Investigation into the influence of boron nitride addition on the properties of SPEEK/PBI based electrolyte membrane

To overcome the limitation of SPEEK/PBI membrane, BN was introduced to the membrane in different percentages. Firstly, boron nitride was functionalized by introducing hydroxyl group using KMNO4, H2O2, as oxidation agents. At the same time SPEEK was prepared by sulfonating PEEK at 80 °C using sulfonic acid. Further, a SPEEK/PBI/BN blend was prepared by dissolving SPEEK/BN in DMCs and then mixed with PBI heated solution. The percentage of the BN were 10%, 15 and 20%. The prepared membranes were characterized, however, SPEEK/PBI/BN-10% showed the optimum physicochemical properties; in which the degree of sulfonating, ion exchange capacity, water uptake, tensile stress, ionic conductivity, and thermal stability were 80.53%, 2.18 meq.g−1, 6.13%,8.61 MPa, 245 mS/cm, and 316.6 °C. The results show that the addition of BN influenced the characteristics of the membrane remarkably in a positive way as the protonic conductivity increased remarkably from 170 mS/cm to 245 mS/cm. Moreover, there was a huge enhancement in the thermal stability and the ionic conductivity.

Mitigation potential of individual and combined dietary supplementation of local Bentonite Clay and Distillery Sludge against Ochratoxin-A induced toxicity in broilers

BackgroundThis study aimed to evaluate the ameliorative effects of dietary supplementation of local bentonite clay (BN) and distillery sludge (DS) alone and in combination on ochratoxin-A (OTA) induced toxicity in broilers. For this purpose, day-old-broiler chicks (n = 270) were procured from the local market and reared under standard management conditions. After 7 days of acclimatization, birds were divided into 2 main groups A and B with respect to OTA inclusion level in feed, each with four sub-groups viz. A1-A4, each challenged with OTA at a dietary inclusion level of 250 µg/kg feed and B1-B4, each challenged with OTA at the level of 500 µg/kg feed and a common control group that was fed with basal feed throughout the experiment. In groups A and B, BN and DS were administered with feed at the rate of 10 g/kg of feed and 5 g/kg of feed alone and in combination, respectively.ResultsResults showed that OTA administration alone resulted in poor feed conversion ratio (FCR) and immunological responses along with increased serum levels of alanine transaminase (ALT), Aspartate transaminase (AST), urea and creatinine (P < 0.05). A significant decrease (P < 0.05) in serum protein levels (albumin, globulin and total protein) was also observed in OTA-fed groups in a dose-dependent manner. The addition of BN at 10 g/kg of OTA-contaminated feed resulted in better FCR and immunological responses as compared to those fed OTA only. The BN supplementation also conferred protection against elevation of serum biochemical parameters when compared with OTA-fed groups. However, the addition of DS could not provide significant protection (P > 0.05) on alteration of serum biochemical parameters in response to the OTA induced toxicity. The combined supplementation of BN and DS resulted in amelioration of OTA-induced toxicity and showed improved FCR, immunological, hematological and serum biochemical parameters (P < 0.05) when compared with other groups. Similarly, BN and DS resulted in a significant decline (P < 0.05) in the OTA tissue residues compared with other groups and control.ConclusionIn conclusion, combined dietary supplementation of BN (10 mg/kg) and DS (05 mg/kg) in feed reduced the toxic effects of OTA contamination at levels of 250 and 500 µg/kg of feed in broilers. So, the combination products of BN and DS may be successfully developed for use in poultry for protection against OTA-induced toxicity in broilers.

Investigation of the mechanical properties and corrosion behaviors of Ni-BN-TiC layers constructed via laser cladding technique

In this article, Ni and Ni-BN-TiC layers were constructed using laser cladding technique (LCT). The microstructure, phase structure, microhardness, elastic modulus, thermal stability, and corrosion behaviors of Ni-BN-TiC layers were investigated using scanning electron microscope (SEM), X-ray diffractometer (XRD), nanoindentation, differential scanning calorimetry (DSC), and electrochemical workstation. The results indicated that Ni-BN-TiC layers possessed a fine and compact microstructure. The exothermic peak of the Ni-BN-TiC layer appeared at 461°C, indicating the highest thermal stability. The mechanical properties of Ni-BN-TiC layer improved with the addition of BN and TiC particles, having an average microhardness of 19.6 GPa, and average elastic modulus of 194.2 GPa. In addition, the corrosion current densities of 45 steel, Ni and Ni-BN-TiC layers were 4.808 μA/cm2, 3.917 μA/cm2, and 2.014 μA/cm2, respectively. The corrosion potentials and corrosion current densities results showed the outstanding corrosion resistance of Ni-BN-TiC layers.

Magnetic and microstructural modification of the Dy-free HDDR Nd-Fe-B powders with micron BN addition by the grain boundary diffusion engineering

The micron BN powders were studied as diffusion sources for the grain boundary diffusion process to HDDR (hydrogenation-disproportionation-desorption-recombination) Nd-Fe-B powders. The coercivity of HDDR powders was enhanced by about 52.1 %. The only downside is that the remanence was slightly reduced because BN powders were a non-magnetic additive. Microstructural investigations showed that the nonferromagnetic Nd-rich grain boundary phases envelop the Nd2Fe14B grains because the wettability of the interface between the matrix and the grain boundary phases was improved by diffusing BN powders. The preferred residence of BN in the intergranular phases and their reaction with the grain boundary phases might both contribute to the enhancement of the coercivity. As a result, the research and development of the grain boundary diffusion process with non-rare earth materials have significance in further minimizing the use of rare earth (RE).

Improving the mechanical performance of adhesively bonded CFRP composite joints exposed to harsh mediums with the reinforcement of boron nanostructures

In this study, the degradation in the strength of adhesively bonded carbon fibre composite joints exposed to different harsh mediums was improved with the addition of silane-modified BN and B4C nanostructures. For this purpose, modified BN and B4C nanostructures were added to the structural adhesive, and then composite plates were bonded with the new reinforced adhesives to produce single lap joints. The produced joints were aged 480, 960, and 1440 h in distilled water, saltwater, sulphuric acid, and ultraviolet light mediums. The mechanical properties of the joints were determined by the tensile test after aging. Moreover, liquid absorption and SEM analyses were performed to observe the structural change in the adhesives. The results revealed that adding nanostructures into the epoxy matrix positively decreases the absorption of distilled water, saltwater, and sulphuric acid solutions. It was also observed that the failure loads of joints decreased depending on the severity of the damage caused by the aging mediums. The joints bonded with BN and B4C nanostructures reinforced adhesives decreased the damage experienced by limiting the harmful effects of the mediums. After 1440 h of aging in the distilled water medium, the composite joints reinforced with BN and B4C nanostructures carried approximately 40% and 37.6% higher loads, respectively, compared to the neat joint. Similarly, as a result of the aging in the UV medium, BN and B4C reinforced joints carried approximately 48.3% and 40.9% higher loads, respectively, while these ratios were determined as 39.7% and 36.7%, respectively, for the saltwater medium.

High strength and ductility of titanium matrix composites by nanoscale design in selective laser melting

• SLM parameters play a major role in densification and microstructure. • Nanosized secondary particle additions promote densification. • Nanosized BN additions produce fine, high aspect ratio TiB reinforcement. • TiB morphological evolution during SLM and heat treatment impacts properties. • High tensile strength and ductility through high aspect ratio TiB nanowhiskers. The use of selective laser melting (SLM) to produce titanium matrix composites (TMCs) with high strength while retaining sufficient tensile ductility suitable for structural applications is emerging as an attractive opportunity in the field of advanced manufacturing. However, the presence of coarse ceramic reinforcements as well as difficulties in optimizing the SLM process is a barrier to the application of TMCs. In this study, we demonstrated the production of TMCs reinforced with in situ high aspect ratio TiB nanowhiskers by selective laser melting using nanosized BN powder additions. Pure Ti with 2.5 vol.% nanosized BN powder showed promise for producing high performance TMCs with retained ductility. BN acted to produce TiB nanowhiskers with diameter < 50 nm. Further, by controlling post process furnace annealing TiB retained a low diameter but exhibited a high aspect ratio, up to 400. In addition to TiB refinement, nanosized BN addition promoted grain refinement during SLM, both acting as a solute to induce nucleation events and, as TiB is formed, providing nucleation sites leading to an ultrafine grain structure in as printed samples and after annealing. The produced TMCs exhibit high tensile yield strength, up to 1392 MPa, while retaining tensile ductility up to 10%. This study has shown how nanoscale design in powder bed fusion additive manufacturing techniques can be used to produce high performance TMCs through a combination of refined grain structure and high aspect ratio TiB leading to TMCs with significant improvement in strength, isotropic properties and retained tensile ductility.

MgB2 with Addition of Cubic BN and Ge2C6H10O7 Obtained by Spark Plasma Sintering Technique

MgB2 with Addition of Cubic BN and Ge2C6H10O7 Obtained by Spark Plasma Sintering Technique

Enhanced Sinterability, Thermal Conductivity and Dielectric Constant of Glass-Ceramics with PVA and BN Additions.

With the rapid development of the microelectronics industry, many efforts have been made to improve glass-ceramics’ sinterability, thermal conductivity, and dielectric properties, which are essential components of electronic materials. In this study, low-alkali borosilicate glass-ceramics with PVA addition and glass-BN composites were prepared and successfully sintered at 770 °C. The phase composition, density, microstructure, thermal conductivity, and dielectric constant were investigated. It was shown that PVA addition contributes to the densification process of glass-ceramics (~88% relative density, with closed/open pores in the microstructure) and improves the thermal conductivity of glass material from 1.489 to 2.453 W/K.m. On the other hand, increasing BN addition improves microstructures by decreasing porosities and thus increasing relative densities. A glass-12 wt. % BN composite sample exhibited almost full densification after sintering and presented apparent and open pores of 2.6 and 0.08%, respectively. A high thermal conductivity value of 3.955 W/K.m and a low dielectric constant of 3.00 (at 5 MHz) were observed in this material. Overall, the resulting glass-ceramic samples showed dielectric constants in the range of 2.40–4.43, providing a potential candidate for various electronic applications.