scholarly journals Investigation of the Physical and Mechanical Properties of Hot-Pressed Boron Nitride/Oxide Ceramic Composites

1999 ◽  
Vol 82 (9) ◽  
pp. 2563-2565 ◽  
Author(s):  
Rodney W. Trice ◽  
John W. Halloran
Keyword(s):  
Mechanical Properties ◽  
Boron Nitride ◽  
Physical And Mechanical Properties ◽  
Ceramic Composites ◽  
Oxide Ceramic ◽  
Nitride Oxide

Structure and properties of compact articles from high-alloyed iron powder with adding of boron nitride

2020 ◽  
pp. 39-48
Author(s):  
B. O. Bolshakov ◽  
◽  
R. F. Galiakbarov ◽  
A. M. Smyslov ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Boron Nitride ◽  
Grain Boundary ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Operating Conditions ◽  
Structure And Properties ◽  
Steam Turbines ◽  
Friction Forces ◽  
Wide Range

The results of the research of structure and properties of a composite compact from 13 Cr – 2 Мо and BN powders depending on the concentration of boron nitride are provided. It is shown that adding boron nitride in an amount of more than 2% by weight of the charge mixture leads to the formation of extended grain boundary porosity and finely dispersed BN layers in the structure, which provides a high level of wearing properties of the material. The effect of boron nitride concentration on physical and mechanical properties is determined. It was found that the introduction of a small amount of BN (up to 2 % by weight) into the compacts leads to an increase in plasticity, bending strength, and toughness by reducing the friction forces between the metal powder particles during pressing and a more complete grain boundary diffusion process during sintering. The formation of a regulated structure-phase composition of powder compacts of 13 Cr – 2 Mо – BN when the content of boron nitride changes in them allows us to provide the specified physical and mechanical properties in a wide range. The obtained results of studies of the physical and mechanical characteristics of the developed material allow us to reasonably choose the necessary composition of the powder compact for sealing structures of the flow part of steam turbines, depending on their operating conditions.

Boron nitride for modification of rubber based on isoprene elastomer

2020 ◽  
pp. 105-112
Author(s):  
K. S. Zhansakova ◽  
E. N. Eremin ◽  
G. S. Russkikh ◽  
O. V. Kropotin
Keyword(s):  
Mechanical Properties ◽  
Boron Nitride ◽  
Gradual Increase ◽  
Physical And Mechanical Properties ◽  
Curing Time ◽  
Cross Link ◽  
Start Time ◽  
Link Density ◽  
Cross Link Density ◽  
Isoprene Rubber

The work studies vulcanization characteristics of elastomers based on isoprene rubber filled with carbon black N330 and boron nitride (BN). The influence of the boron nitride (BN) concentration on technological, dynamic, physical and mechanical properties of elastomers has been researched. The application of boron nitride for producing rubber with good properties has been considered. With a gradual increase of the inert filler BN concentration up to 35%, a decrease in the curing rate by 33% and polymer cross-link density by 26% is observed. Moreover, the start time of vulcanization increases by almost 300%, the optimal curing time by 200%.

scholarly journals Porogen Effect of Bioactive Glass on Poly(L-lactide) Scaffolds: Evidences by Electron Microscopy

2008 ◽  
Vol 14 (S3) ◽  
pp. 65-66
Author(s):  
N.B. Barroca ◽  
A.L. Daniel-da-Silva ◽  
M.H.V. Fernandes ◽  
P.M. Vilarinho
Keyword(s):  
Mechanical Properties ◽  
Bioactive Glass ◽  
Average Pore Size ◽  
Physical And Mechanical Properties ◽  
Ceramic Composites ◽  
Porous Polymer ◽  
Bioactive Glasses ◽  
Average Pore ◽  
Thermally Induced ◽  
Ceramic Fillers

Recently, porous polymer-ceramic composites have been developed and represent promising scaffolds to be used as synthetic extracellular matrix in bone tissue engineering since they combine the advantages of these two types of materials. On the other hand bioactive glasses (BG) have been used as ceramic fillers to promote bioactivity and to enhance mechanical properties and osteoblast functions. Among all the requirements, these 3D porous structures should have a controllable average pore size larger than 100 μm as well as good pore interconnectivity to allow vascularization and tissue ingrowth. The goal of this study is to investigate the effect of the addition of a bioactive glass on the porous structure development of the scaffolds prepared by thermally induced phase-separation and also to test the bioactivity of these composite scaffolds. Poly (L-lactic) acid (PLLA) was chosen as the polymer matrix because of its well-known biocompatibility and adjustable physical and mechanical properties. Micron-sized (<10 μm) glass from the 3CaO.P2O5-MgO-SiO2 system was produced in our laboratory and used as the bioactive ceramic filler.

An Image-Based Microscale Simulation of Thermal Residual Stresses in DSE Oxide Ceramic Composite

2011 ◽  
Vol 189-193 ◽  
pp. 1681-1686 ◽  
Author(s):  
Jian Jun Sha ◽  
S. Ochiai ◽  
H. Okuda ◽  
S. Iwamoto ◽  
K. Morishita ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Finite Element Method ◽  
Thermal Expansion ◽  
Residual Stresses ◽  
Ceramic Composite ◽  
Ceramic Composites ◽  
Oxide Ceramic ◽  
Directionally Solidified ◽  
Thermal Residual Stresses ◽  
Good Agreement

An image-based microscale analysis was conducted by using finite element method (FEM) to simulate the thermal residual stresses in directionally solidified eutectic (DSE) oxide ceramic composites from the thermal expansion and elastic properties and the microstructure features of the constituent phases. This microscale analysis allows a real simulation of morphologies of constituent phases such as size, array and shape. Meanwhile, this model can be applied not only for the calculation of thermal residual stresses, but also for the calculation of mechanical properties. In this work, simulations focus on the distribution of thermal residual stresses in the directionally solidified eutectic (DSE) Al2O3/ Y3Al5O12 (YAG) ceramic composite. A good agreement between simulated and measured thermal residual stresses was observed.

scholarly journals Improvement in the physical and mechanical properties of the cement-based composite with the addition of nanostructured BN–Fe3O4 reinforcement

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Siavash Imanian Ghazanlou ◽  
Siamak Imanian Ghazanlou ◽  
Warda Ashraf
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Iron Oxide ◽  
Boron Nitride ◽  
Mechanical Strength ◽  
Physical And Mechanical Properties ◽  
Simultaneous Thermal Analysis ◽  
Inorganic Nanoparticles ◽  
Cement Matrix ◽  
Hybrid Filler

AbstractIn this work, the performance of modified cement by nanostructures consisting of boron nitride (BN) and iron oxide inorganic nanoparticles (Fe3O4) was analyzed. The mechanical strength, electrical resistivity, and the degree of cement hydration as well as the microstructure were investigated in detail. A hybrid filler boron nitride-iron oxide (BN–F) composed of Fe3O4 and BN was successfully synthesized using a chemical reaction. Transmission electron microscope (TEM) results showed proper binding of BN–F nanostructures. Addition of the hybrid nanostructured BN–F5 (containing 0.5 wt.% Fe3O4 and 0.5 wt.% BN) into the cement matrix increased the compressive strength and flexural strength by 65%, and 74%, respectively, after 28 days of curing. The improvement in mechanical strength is attributed to the increased surface friction induced by the Fe3O4 nanoparticles on the BN surfaces, resulting in increased interaction with the matrix. Microstructural studies, such as scanning electron microscope (SEM), showed the formation of a dense structure due to improved dispersion in the cement environment and hybrid performance in preventing crack growth, which is the main reason for the overall improvement in mechanical properties. The concrete resistance gauge (RCON, Giatec) and simultaneous thermal analysis (STA) tests revealed a significant increase in thermal and electrical conductivity in composite reinforced with nanostructured BN–F.

scholarly journals Effect of Hexagonal Boron nitride Nanopowder Reinforcement and Mixing Methods on Physical and Mechanical Properties of Self-Cured PMMA for Dental Applications

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2323 ◽  
Author(s):  
Mana Alqahtani
Keyword(s):  
Mechanical Properties ◽  
Boron Nitride ◽  
Flexural Strength ◽  
Hexagonal Boron Nitride ◽  
Dental Materials ◽  
Physical And Mechanical Properties ◽  
Future Research ◽  
Infrared Spectrometry ◽  
Mixing Method

We report for the first time on the effect of biocompatible hexagonal boron nitride (h-BN) nanopowder reinforcement with different concentrations on the structural and mechanical properties of fabricated self-cured polymethyl methacrylate (PMMA) based dental materials (GC UNIFAST III). A comparison among the structural and mechanical properties between hand and ultrasonic mixing is also presented. Fabricated specimens were studied by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectrometry (FTIR), micro indentation, and flexural strength techniques. The ultrasonic mixing method provides better sample textures of the composite as compared to hand mixing. It is found that XRD and IR intensity of the peaks increases with the increase of h-BN concentration due to nanocomposite formation. The additions of h-BN nanoparticles to the acrylic resin enhanced the hardness and the flexibility values of the composites. Independently of the mixing method used, adding h-BN nanopowder relatively increases the Vickers Hardness numbers (VH) and Flexural Strength (FS) of the unmodified materials. However, using ultrasonic mixing method combined with h-BN nanopowder increases VH numbers to 300% and FS values to 550% with respect to the unmodified sample made by hand mixing. The results obtained are very encouraging and will support future research in vivo, to confirm whether PMMA loaded with h-BN nanoparticles is an improvement compared to current dental restorative materials.

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