In this paper the microstructure and mechanical properties of two different Cf/ZrB2-SiC composites reinforced with continuous PyC coated PAN-derived fibres or uncoated pitch-derived were compared. Pitch-derived carbon showed a lower degree reaction matrix phase during sintering compared to PyC/PAN-derived fibres. The reason lies in carbon. presence coating for was found be essential limit at fi...

Microstructure-controlled and fully-dense ZrB2 HfB2 composites were elaborated by Spark Plasma Sintering with two different amounts of SiC (20 30 vol%) added to improve their oxidation resistance using optimized sintering parameters. Oxidation several samples in air plasma conditions, at 1000 Pa total pressure from 1800 K up 2600 K, was carried out. The mass variation during duration 300 s on a...

This work aims at studying the effect of the milling conditions on the microstructure and mechanical properties of a ZrB₂-5 vol% Si₃N₄ matrix reinforced with chopped Hi-Nicalon SiC fibers. Several composites were obtained using different milling conditions in terms of time, speed and type of milling media. The composites were prepared from commercial powders, ball milled, dried and shaped, and ...

1.—Department of Physics and Astronomy, Youngstown State University, Youngstown, OH 44555, USA. 2.—Department of Physics, Georgia Southern University, Statesboro, GA 30460, USA. 3.—Department of Physics, Auburn University, Auburn, AL 36849, USA. 4.—Present address: Department of Materials Science and Engineering, University of Illinois at Urbana– Champaign, Urbana, IL 61801, USA. 5.—e-mail: tno...

The aqueous dispersion behavior of ZrB₂, SiC powders with B₄C and C as sintering aids was investigated. Well co-dispersed suspension can be obtained in acidic solutions in presence of polyethyleneimine (PEI). The adsorption of PEI on the powder surface was measured by thermal gravimetric (TG) analysis. Rheological measurements displayed the effect of dispersant on the flow behavior of as-prepar...

ZrB2-20 vol.% SiC-10 vol.% h-BN (particles) ceramic composites (ZSB) were fabricated by hot pressing under inert gas protected. ZSB samples with mean size 75 × 55 × 40 mm(3) were heated using current heating method and then cooled down to low temperature by circulating water. ZSB samples repeatedly went through thermal shock with 10-50 times under various conditions, respectively. Diverse effec...