Homogeneous dispersion of boron nitride nanoplatelets in powder feedstocks for plasma spraying

Author(s):  
Xiaolong Lu ◽  
Cheng Zhang ◽  
Arvind Agarwal ◽  
Yao Chen
2016 ◽  
Vol 680 ◽  
pp. 21-24
Author(s):  
Mei Lin Gao Sun ◽  
Ping Wu ◽  
Hai Jian Li

Boron nitride materials have some excellent features, such as high temperature resistance, chemical resistance, good electric performance and radiation resistance . Along with the development of science and technology, boron nitride materials are made into coating widely, put it in the surface of metallic materials or non-metallic materials, can extend their service life significantly[1]. Atomic force microscope (AFM) is widely used for nanoscale morphology characterization and submicron scale structure material, simple sample preparation is its advantage. [2] Based on the domestic boron nitride coating as the research background, using AFM simulate the surface nanostructures of three dimensional, and evaluate the flatness of boron nitride ceramic coating which made by plasma spraying method and chemical vapor phase precipitation method respectively. The results show that the coating prepared with plasma spraying is more dense, surface flatness is smaller, surface roughness uniformity is better.


2016 ◽  
Vol 116 ◽  
pp. 155-165 ◽  
Author(s):  
K. Madhav Reddy ◽  
Chawon Hwang ◽  
Metin Ornek ◽  
Steven L. Miller ◽  
William E. Mayo ◽  
...  

Author(s):  
K.R. Subramanian ◽  
A.H. King ◽  
H. Herman

Plasma spraying is a technique which is used to apply coatings to metallic substrates for a variety of purposes, including hardfacing, corrosion resistance and thermal barrier applications. Almost all of the applications of this somewhat esoteric fabrication technique involve materials in hostile environments and the integrity of the coatings is of paramount importance: the effects of process variables on such properties as adhesive strength, cohesive strength and hardness of the substrate/coating system, however, are poorly understood.Briefly, the plasma spraying process involves forming a hot plasma jet with a maximum flame temperature of approximately 20,000K and a gas velocity of about 40m/s. Into this jet the coating material is injected, in powder form, so it is heated and projected at the substrate surface. Relatively thick metallic or ceramic coatings may be speedily built up using this technique.


Author(s):  
X. Qiu ◽  
A. K. Datye ◽  
T. T. Borek ◽  
R. T. Paine

Boron nitride derived from polymer precursors is of great interest for applications such as fibers, coatings and novel forms such as aerogels. The BN is prepared by the polymerization of functionalized borazine and thermal treatment in nitrogen at 1200°C. The BN powders obtained by this route are invariably trubostratic wherein the sheets of hexagonal BN are randomly oriented to yield the so-called turbostratic modification. Fib 1a and 1b show images of BN powder with the corresponding diffraction pattern in fig. 1c. The (0002) reflection from BN is seen as a diffuse ring with occational spots that come from crystals of BN such as those shown in fig. 1b. The (0002) lattice fringes of BN seen in these powders are the most characteristic indication of the crystallinity of the BN.


Author(s):  
D. L. Medlin ◽  
T. A. Friedmann ◽  
P. B. Mirkarimi ◽  
M. J. Mills ◽  
K. F. McCarty

The allotropes of boron nitride include two sp2-bonded phases with hexagonal and rhombohedral structures (hBN and rBN) and two sp3-bonded phases with cubic (zincblende) and hexagonal (wurtzitic) structures (cBN and wBN) (Fig. 1). Although cBN is synthesized in bulk form by conversion of hBN at high temperatures and pressures, low-pressure synthesis of cBN as a thin film is more difficult and succeeds only when the growing film is simultaneously irradiated with a high flux of ions. Only sp2-bonded material, which generally has a disordered, turbostratic microstructure (tBN), will form in the absence of ion-irradiation. The mechanistic role of the irradiation is not well understood, but recent work suggests that ion-induced compressive film stress may induce the transformation to cBN.Typically, BN films are deposited at temperatures less than 1000°C, a regime for which the structure of the sp2-bonded precursor material dictates the phase and microstructure of the material that forms from conventional (bulk) high pressure treatment.


2021 ◽  
Vol 23 (1) ◽  
pp. 219-228
Author(s):  
Nabanita Saikia ◽  
Mohamed Taha ◽  
Ravindra Pandey

The rational design of self-assembled nanobio-molecular hybrids of peptide nucleic acids with single-wall nanotubes rely on understanding how biomolecules recognize and mediate intermolecular interactions with the nanomaterial's surface.


Author(s):  
I.B. Karymsakova ◽  
◽  
Iu.V. Krak ◽  
N.F. Denissova ◽  
◽  
...  
Keyword(s):  

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