scholarly journals Corrosion resistance of inconel 690 to borax, boric acid, and boron nitride at 1100{degrees}C

1996 ◽  
Author(s):  
K Imrich
Keyword(s):  
Corrosion Resistance ◽  
Boron Nitride ◽  
Boric Acid ◽  
Inconel 690

Optimal plasma process routes for boron nitride (BN) powder production from boric acid (H3BO3)

2000 ◽  
Vol 26 (2) ◽  
pp. 165-170 ◽  
Author(s):  
Života G. Kostić ◽  
Predrag Lj. Stefanović ◽  
Pavle B. Pavlović ◽  
Dejan B. Cvetinović ◽  
Slobodan Đ. Šikmanović
Keyword(s):  
Boron Nitride ◽  
Boric Acid ◽  
Plasma Process ◽  
Powder Production

Preparation of hexagonal BN whiskers synthesized at low temperature and their application in fabricating an electrochemical nitrite sensor

RSC Advances ◽  
2016 ◽  
Vol 6 (33) ◽  
pp. 27767-27774 ◽  
Author(s):  
Wenpo Luo ◽  
Tao Yang ◽  
Lei Su ◽  
Kuo-Chih Chou ◽  
Xinmei Hou
Keyword(s):  
Low Temperature ◽  
Boron Nitride ◽  
Boric Acid ◽  
Hexagonal Boron Nitride ◽  
Raw Materials ◽  
Polymeric Precursor Method ◽  
Polymeric Precursor ◽  
Precursor Method ◽  
Nitrite Sensor

Hexagonal boron nitride (h-BN) whiskers were synthesized via the polymeric precursor method using boric acid (H3BO3) and melamine (C3H6N6) as raw materials at 1073–1273 K in flowing nitrogen/hydrogen (5% hydrogen).

Preparation of the Boron Nitride Fibers by Chemical Reaction

2009 ◽  
Vol 66 ◽  
pp. 191-193 ◽  
Author(s):  
Zhi Qiang Cheng ◽  
Hong Lin Yu ◽  
Ling Li ◽  
Yong Li ◽  
Xiao Li Zhang ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Elastic Modulus ◽  
Boron Nitride ◽  
Boric Acid ◽  
Nitrogen Content ◽  
Chemical Reaction ◽  
Chemical Method ◽  
Raw Material

In this study, boron nitride (BN) fibers were prepared via chemical method using boric acid as the raw material, under the atmosphere of NH3 and N2, respectively. Firstly, the boric acid was heated to melt in order to acquire B2O3 fibers. Secondly, the B2O3 fibers were pre-azotized under a NH3 atmosphere and held for 1 h at 970°C, and the sample was then sintered in N2 to the temperature of 2000°C and held for 1 h. The obtained samples were texted to analyze nitrogen content, morphology, tensile strength, and elastic modulus by neutralization titration, SEM, XRD and so on. The results show that the diameter of the BN fibers is ~ 4-6 μm with the nitrogen content of 54%, tensile strength of 1400 MPa, and elastic modulus of 120 GPa.

Polycondensation of Urea and Boric Acid to Give Polyborate Ester, a Precursor for Boron Nitride

2007 ◽  
Vol 29-30 ◽  
pp. 199-202 ◽  
Author(s):  
S. Mondal ◽  
A.K. Banthia
Keyword(s):  
Boron Nitride ◽  
Boric Acid ◽  
Elemental Analysis ◽  
High Performance ◽  
Powder Processing ◽  
Condensation Reaction ◽  
Ceramic Materials ◽  
Attractive Alternative ◽  
Condensation Polymerization ◽  
Multifunctional Compounds

Polycondensations (condensation polymerization) are stepwise reactions between bifunctional or polyfunctional compoents, with elimination of simple molecules such as water or alcohol and the formation of macromolecular substances. Polyborate ester , formed by this process, gives ceramic materials during pyrolysis. Polymer pyrolysis offers an attractive alternative to the typical high temperature powder processing approach in the fabrication of high-performance ceramics. This approach might also prove to be useful in the fabrication of fibers, coatings, and composites. It is within this framework that the present study was undertaken; its aim is the preparation of boron-containing oligomeric precursors which gives boron nitride after pyrolysis. The precursor was synthesized by the condensation reaction between boric acid and urea (or other N-containing reactive multifunctional compounds). The oligomeric precursor and its pyrolysed products were thoroughly characterized by elemental analysis, IR, NMR, XRD, Thermal Analysis and Transmission Electron Microscopy(TEM). The elemental analysis results of the oligomer are---- C-13.40%, H-5.97%, N-32.44% and B-17.09%. X-ray diffraction and TEM studies showed that boron nitride obtained from this system possess tetragonal structure.

Effect of Boron Nitride on the Mechanical and Electrochemical Properties of Cement Composite

2015 ◽  
Author(s):  
Qinyue He ◽  
Xun Yu
Keyword(s):  
Corrosion Resistance ◽  
Boron Nitride ◽  
Electrochemical Properties ◽  
Hexagonal Boron Nitride ◽  
Water Solution ◽  
Cement Composite ◽  
Sodium Cholate ◽  
Ionic Surfactant ◽  
Cement Composites ◽  
Cement Concrete

Hexagonal boron nitride (h-BN) is well known for its unique properties, such as high thermal conductivity, excellent mechanical strength, high electrical insulating, and high chemical stability. This paper studies the effect of h-BN to the mechanical and electrochemical properties of cement concrete. Sodium cholate is used as an ionic surfactant to exfoliate h-BN and subsequently stabilize them in water solution. Different cement concrete samples with different doping levels of h-BN and different sizes of h-BN were prepared for comparisons. Also, steel fiber reinforced h-BN/cement concrete samples were also prepared. The results show that the addition of h-BN can improve the strength of cement composites, and the degree of reinforcement are influenced by the doping levels and feature size of h-BN. The corrosion resistance of h-BN/cement composites were also tested. Experiments results show that h-BN can enhance the corrosion resistance of cement composites.

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