Fine-diameter Si–B–C–N ceramic fibers enabled by polyborosilazanes with N–methyl pendant group

New ceramic fibers, currently in various stages of commercial development, have been consolidated in intermetallic matrices such as γ-TiAl and FeAl. Fiber types include SiC, TiB2 and polycrystalline and single crystal Al2O3. This work required the development of techniques to characterize the thermochemical stability of these fibers in different matrices.SEM/EDS elemental mapping was used for this work. To obtain qualitative compositional/spatial information, the best realistically achievable counting statistics were required. We established that 128 × 128 maps, acquired with a 20 KeV accelerating voltage, 3 sec. live time per pixel (total mapping time, 18 h) and with beam current adjusted to give 30% dead time, provided adequate image quality at a magnification of 800X. The maps were acquired, with backgrounds subtracted, using a Noran TN 5500 EDS system. The images and maps were transferred to a Macintosh and converted into TIFF files using either TIFF Maker, or TNtolMAGE, a Microsoft QuickBASIC program developed at the Science Center. From TIFF files, images and maps were opened in either NIH Image or Adobe Photoshop for processing and analysis and printed from Microsoft Powerpoint on a Kodak XL7700 dye transfer image printer.

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A TEM investigation of silicon nitride whiskers

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100125737 ◽

1987 ◽

Vol 45 ◽

pp. 160-161

Author(s):

Tapan Roy

Keyword(s):

Silicon Nitride ◽

High Resolution ◽

Ceramic Matrix Composites ◽

High Resolution Electron Microscopy ◽

Molten Silicon ◽

Matrix Composites ◽

Ceramic Fibers ◽

Resolution Electron ◽

Point To Point ◽

Technological University

Ceramic fibers are being used to improve the mechanical properties of metal matrix and ceramic matrix composites. This paper reports a study of the structural and other microstructural characteristics of silicon nitride whiskers using both conventional TEM and high resolution electron microscopy.The whiskers were grown by T. E. Scott of Michigan Technological University, by passing nitrogen over molten silicon in the presence of a catalyst. The whiskers were ultrasonically dispersed in chloroform and picked up on holey carbon grids. The diameter of some whiskers (<70nm) was small enough to allow direct observation without thinning. Conventional TEM was performed on a Philips EM400T while high resolution imaging was done on a JEOL 200CX microscope with a point to point resolution of 0.23nm.

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Ceramic fibers from hydridopolysilazane

Journal de Chimie Physique ◽

10.1051/jcp/1986830869 ◽

1986 ◽

Vol 83 ◽

pp. 869-873 ◽

Cited By ~ 4

Author(s):

Gary E. Legrow ◽

F. Lim ◽

J. Lipowitz ◽

Ronald S. Reaoch

Keyword(s):

Ceramic Fibers

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406. Exposure to Ceramic Fibers, Cristobalite, Tridymite, and Quartz During Removal of Insulation in an Industrial Furnace

10.3320/1.2762814 ◽

1999 ◽

Author(s):

D.R. Keenan ◽

J. Hendrix

Keyword(s):

Industrial Furnace ◽

Ceramic Fibers

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Novel Nanostructure Composite Dielectric with High Insulation Performance: Silica-Based Nanometer-Sized Porous Composite Insulating Paper Reinforced by Ceramic Fibers

SSRN Electronic Journal ◽

10.2139/ssrn.3478088 ◽

2019 ◽

Author(s):

Wenxia Sima ◽

Jiahui He ◽

Potao Sun ◽

Ming Yang ◽

Ze Yin ◽

...

Keyword(s):

Ceramic Fibers ◽

Porous Composite ◽

Insulating Paper ◽

High Insulation ◽

Insulation Performance

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Injection Molding and Near-Complete Densification of Monolithic and Al2O3 Fiber-Reinforced Ti2AlC MAX Phase Composites

Materials ◽

10.3390/ma14133632 ◽

2021 ◽

Vol 14 (13) ◽

pp. 3632

Author(s):

Sylvain Badie ◽

Rimy Gabriel ◽

Doris Sebold ◽

Robert Vaßen ◽

Olivier Guillon ◽

...

Keyword(s):

Injection Molding ◽

Graphite Powder ◽

Max Phase ◽

Powder Injection ◽

Fiber Reinforced ◽

Ceramic Fibers ◽

Plasma Sintering ◽

Molded Parts ◽

Al2o3 Fiber ◽

Induced Velocity

Near-net shape components composed of monolithic Ti2AlC and composites thereof, containing up to 20 vol.% Al2O3 fibers, were fabricated by powder injection molding. Fibers were homogeneously dispersed and preferentially oriented, due to flow constriction and shear-induced velocity gradients. After a two-stage debinding procedure, the injection-molded parts were sintered by pressureless sintering at 1250 °C and 1400 °C under argon, leading to relative densities of up to 70% and 92%, respectively. In order to achieve near-complete densification, field assisted sintering technology/spark plasma sintering in a graphite powder bed was used, yielding final relative densities of up to 98.6% and 97.2% for monolithic and composite parts, respectively. While the monolithic parts shrank isotropically, composite assemblies underwent anisotropic densification due to constrained sintering, on account of the ceramic fibers and their specific orientation. No significant increase, either in hardness or in toughness, upon the incorporation of Al2O3 fibers was observed. The 20 vol.% Al2O3 fiber-reinforced specimen accommodated deformation by producing neat and well-defined pyramidal indents at every load up to a 30 kgf (~294 N).

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