A facile method to prepare ZrC ceramic fibers by centrifugal melt-spinning using zirconium-containing polymeric precursors

A processable polyborazine precursor was synthesized via substitution reaction and deamine condensation reaction by using methylamine, propylamine and B-trichloroborazine (TCB) as the starting materials. The chemical composition, structure and properties of the obtained polymer were investigated using element analysis, FT-IR, NMR, XPS and TG. The results indicated that the backbone of the polymer was approximate linear arrangement of boron-nitride ring molecules with B-N(CH3)-B structure as bridge bond, meanwhile minor amount of methylamino and propylamino remained in polyborazine as the pendant or end group. The melting point, number average molecular weight and polydispersity index of polyborazine was 90°С , 1002 and 1.355, respectively. The polyborazine showed good processability and polyborazine precursor fibers with diameter of 10~15 µm could be obtained by melt-spinning in N2 atmosphere. The ceramic yield of the polyborazine at 1000°С in nitrogen atmosphere was 53.2 wt%, which suggested that the as-achieved polymer can be used as a precursor to boron nitride ceramic fibers and membranes.

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Structure and Properties of Ceramic Fibers Prepared From Polymeric Precursors [1]

MRS Proceedings ◽

10.1557/proc-73-489 ◽

1986 ◽

Vol 73 ◽

Cited By ~ 3

Author(s):

J. Lipowitz ◽

H. A. Freeman ◽

H. A. Goldberg ◽

R. T. Chen ◽

E. R. Prack

Keyword(s):

High Purity ◽

Structure And Properties ◽

Ceramic Fibers ◽

Chemical Methods ◽

Polymeric Precursors ◽

Conventional Methods ◽

Lower Temperature ◽

Organosilicon Polymers

ABSTRACTCeramics can be prepared by pyrolysis of organosilicon polymers. Advantages of this method of ceramics preparation are; the ability to prepare shapes difficult to achieve by other methods such as fibers and films; the ability to achieve high purity because reagents used to prepare the polymer can be purified by well established chemical methods; processing at lower temperature than conventional methods [2].

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Microstructures and Properties of Ceramic Fibers of h-BN Containing Amorphous Si3N4

Materials ◽

10.3390/ma12233812 ◽

2019 ◽

Vol 12 (23) ◽

pp. 3812

Author(s):

Jing Tan ◽

Min Ge ◽

Shouquan Yu ◽

Zhenxi Lu ◽

Weigang Zhang

Keyword(s):

Dielectric Constant ◽

Tensile Strength ◽

Electron Beam ◽

Melt Spinning ◽

Composite Ceramic ◽

Composite Fibers ◽

Ceramic Fibers ◽

The Mean ◽

Electron Beam Curing ◽

Amorphous Si3n4

Composite ceramic fibers comprising about 80 wt% boron nitride (h-BN) and 20 wt% Si3N4 were fabricated through melt-spinning, electron-beam curing, and pyrolysis up to 1600 °C in atmospheres of NH3 and N2, using a mixture of poly[tri(methylamino)borazine] (PBN) and polysilazane (PSZ). By analyzing the microstructure and composition of the pyrolyzed ceramic fibers, we found the formation of binary phases including crystalline h-BN and amorphous Si3N4. Further investigations confirmed that this heterogeneous microstructure can only be formed when the introduced ratio of Si3N4 is below 30% in mass. The mean modulus and tensile strength of the fabricated composite fibers were about 90 GPa and 1040 MPa, twice the average of the pure h-BN fiber. The dielectric constant and dielectric loss tangent of the composite fibers is 3.06 and 2.94 × 10−3.

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A New Generation of Boron-Based Ceramic Fibers: Design, Processing and Properties of SilicoBoron CarboNitride (SiBCN) Fibers from Boron-Modified Polyvinylsilazanes

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.50.9 ◽

2006 ◽

Vol 50 ◽

pp. 9-16 ◽

Cited By ~ 4

Author(s):

Samuel Bernard ◽

Markus Weinmann ◽

David Cornu ◽

Philippe Miele

Keyword(s):

Melt Spinning ◽

Structural Changes ◽

Fiber Strength ◽

Xrd Analysis ◽

Nitrogen Atmosphere ◽

Ceramic Fibers ◽

Ceramic Yield ◽

Flexible Form ◽

Shaping Process ◽

Spinning Process

Boron-modified polyvinylsilazanes have been studied for suitability as fiber precursor. A melt-tractable polymer displaying Si- and N-bonded methyl groups was successfully processed into green fibers ~18μm in diameter via a melt-spinning process. After the shaping process, the use of an ammonia curing atmosphere at 200°C allowed to increase the ceramic yield of the polymer, then avoid inter-fiber fusion during the further increase of the temperature. As-cured fibers were annealed in the temperature range 1000-1800°C in a nitrogen atmosphere to provide SiBCN ceramic fibers black colored, of flexible form and ~12μm in diameter in different crystallinity states going from totally amorphous below 1600°C to well-crystallized at 1800°C. The excellent strength retention after heat-treatment at 1600°C (1.3-1.5GPa) is clearly related to the high amorphous stability of fibers. Elemental compositions of such amorphous fibers showed a typical chemical formula of Si3.0B1.0C5.0N2.4. Between 1600°C and 1700°C, the fiber strength decreased to 0.9GPa then dropped to about one-quarter the original value at 1800°C while structural changes were evident by XRD analysis.

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Characterization and Microstructural Evolution of Continuous BN Ceramic Fibers Containing Amorphous Silicon Nitride

Materials ◽

10.3390/ma14206194 ◽

2021 ◽

Vol 14 (20) ◽

pp. 6194

Author(s):

Yang Li ◽

Min Ge ◽

Shouquan Yu ◽

Huifeng Zhang ◽

Chuanbing Huang ◽

...

Keyword(s):

Tensile Strength ◽

Silicon Nitride ◽

Melt Spinning ◽

Composite Ceramic ◽

Mass Content ◽

Composite Fibers ◽

Composite Ceramics ◽

Ceramic Fibers ◽

Amorphous Silicon Nitride ◽

The Mean

Boron nitride (BN) ceramic fibers containing amounts of silicon nitride (Si3N4) were prepared using hybrid precursors of poly(tri(methylamino)borazine) (PBN) and polycarbosilane (PCS) via melt-spinning, curing, decarburization under NH3 to 1000 °C and pyrolysis up to 1600 °C under N2. The effect of Si3N4 contents on the microstructure of the BN/Si3N4 composite ceramics was investigated. Series of the BN/Si3N4 composite fibers containing various amounts of Si3N4 from 5 wt% to 25 wt% were fabricated. It was found that the crystallization of Si3N4 could be totally restrained when its content was below 25 wt% in the BN/Si3N4 composite ceramics at 1600 °C, and the amorphous BN/Si3N4 composite ceramic could be obtained with a certain ratio. The mean tensile strength and Young’s modulus of the composite fibers correlated positively with the Si3N4 mass content, while an obvious BN (shell)/Si3N4 (core) was formed only when the Si3N4 content reached 25 wt%.

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Conversion of Chemically-Derived Polymeric Precursors to High performance Ceramic Fibers

MRS Proceedings ◽

10.1557/proc-73-413 ◽

1986 ◽

Vol 73 ◽

Cited By ~ 1

Author(s):

M. Ishaq Haider ◽

Terence J. Clark

Keyword(s):

High Performance ◽

Melt Spinning ◽

Ceramic Materials ◽

Ceramic Fiber ◽

Ceramic Fibers ◽

Research Activity ◽

Fiber Failure ◽

Process Modification ◽

High Performance Fiber ◽

Fiber Reinforcements

ABSTRACTIn recent years, there has been steadily increasing research activity directed towards preparation of ceramic materials via polymer pyrolysis. Among the most thermomechanically stable structural ceramics are SiC, Si3N4, and their solid solutions. These materials are widely used as ceramic fiber reinforcements in composites owing to their high mechanical strength, stiffness, and oxidative stability. Processes have now been developed to make these fibers by utilizing melt spinning. Fine diameter continuous filaments are formed, and further processing involves the steps of mild reactive cure and high-temperature pyrolysis. The approach in this review is to summarize the fiber making process with emphasis on improving fired properties by utilizing known mechanisms of fiber failure and process modification procedures. Fiber characteristics, applications of high performance fiber, and perceived trends will also be discussed.

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Development of Crystallinity in Turbostratic Boron Nitride Derived from Polymeric Precursors

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100089081 ◽

1991 ◽

Vol 49 ◽

pp. 954-955

Author(s):

X. Qiu ◽

A. K. Datye ◽

T. T. Borek ◽

R. T. Paine

Keyword(s):

Thermal Treatment ◽

Boron Nitride ◽

Diffraction Pattern ◽

Polymeric Precursors ◽

Polymer Precursors ◽

Diffuse Ring

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.

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