Fine Ceramic Fibers: From Microstructure to High Temperature Mechanical Behavior

Strength and toughness: The challenging case of TaC-based composites

“…The following commercial powders were used: cubic TaC (Treibacher Industrie AG, Althofen, Austria), mean particle size 1.1 lm; hexagonal TaSi 2 (ABCR GmbH & Co., Karlsruhe, Germany), particle size < 45 lm; tetragonal MoSi 2 (Aldrich, Germany), specific surface area 1.60 m 2 /g, mean particle size 1 lm, impurities: 1 wt% O; a-Si 3 N 4 Baysind (Bayer, Germany), specific surface area 12.2 m 2 /g, impurities: 1.5 wt% O, mean particle size 0.15 lm; b-SiC (Starck BF-12, Germany), specific surface area 11-13 m 2 /g, impurities: 0.88 wt% O mean particle size 0.60 lm. and are constituted by 55% of b-SiC nano crystals, 40% of Si-C-O amorphous metastable phase and 5% graphite [13]. As a consequence of high amount of amorphous phase they have a smooth aspect in Fig.…”

Fracture toughness of Al2O3 fibers with an artificial notch introduced by a focused-ion-beam

“…1,2,8 The density has been reported to be 3.2 g/cm 3 and Young's modulus to be 210 GPa. 1,2,8 The average diameter was 17 m. The fracture surface showed the mirror, mist and hackle zones, as has been shown in (Fig. 1(a)).…”

“…1,2,9,10 The grain size has been reported to be around 0.5 m. 1,2,9 The diameter of this fiber is small (around 10 m), which allows to produce woven cloth from the fiber. 1,2,9,10 The young's modulus has been reported to be 344 GPa. 1,2,9,10 This fiber has lower density of 3.60 g/cm 3 compared to the fully dense ␣-Al 2 O 3 fiber with density 3.92 g/cm 3 , and has intragranular porosities.…”

“…1,2,9,10 The young's modulus has been reported to be 344 GPa. 1,2,9,10 This fiber has lower density of 3.60 g/cm 3 compared to the fully dense ␣-Al 2 O 3 fiber with density 3.92 g/cm 3 , and has intragranular porosities. 1,2,9 Actually, in the fracture surface observed in this work, many micro-porosities were found ( Fig.…”

From random chopped to oriented continuous SiC fibers–ZrB2 composites

“…For this kind of fibers, thus, a protective coating is advisable to ensure a weak matrix/fiber interface and a higher stability of the fiber itself in aggressive environments. On the other hand, Tyranno SA3 SiC fibers are sintered fibers with a lower content of oxygen and non-crystallized Si-C bounds, [17] and recent TEM analyses have shown they are less reactive towards the boride matrix [18] as well as compatible with the use of Si 3 N 4 and ZrSi 2 as sintering aids.…”