Composites: Part B 39(2008)362-373 170nm 2,3Hm 207nm 2,3μm Coated fiber After thermal annealing. Fig 3. Topography of the Nextel 440-fiber, coated with 30 nm BN and 30 nm TiO2 [14(AFM picture). Fig. 4. Principle of composites preparation surface of the capstan. Next, the disks are stacked and Table 3 middle)shows a vacuum furnace to provide reducing or Fiber dirction bonlcar' es preparation dried(Fig. 4, on the right). Hot pressing is carried out in an INSTRON installation. Fig. 4(at the bottom, in the doo of the matrix glass <70um 8-35% also neutral atmosphere during hot pressing. For the Slurry Deionized water without additives matrix glass 8650, which requires oxidizing atmospherePressure during hot pressing, an additional furnace(not shown here) Temperature is available which can be inserted in the hot press. In Fig4 N-SK4-matrix 850°C (down on the left), several composite disks are shown: In Duran-matrix 850°C the middle, a black one(1) with C-coated fibers, then two white ones(2) whose optical and thermal properties of 8650-matrix the fibers and the matrix glass are not adapted, and four Atmosphere translucent disks(3)with differently -in any case better N-SK4-matrix roperties Table 3 shows an overview of the manufacturing param 8650matrix eters employed. The hot pressing temperature is mainly influenced by the transformation temperature Tg of results presented in this paper were all obtained in tests car matrix glass. The pressure varied from 5 to 15 MPa ried a pressure of 5 MPasurface of the capstan. Next, the disks are stacked and dried (Fig. 4, on the right). Hot pressing is carried out in an INSTRON installation. Fig. 4 (at the bottom, in the middle) shows a vacuum furnace to provide reducing or also neutral atmosphere during hot pressing. For the matrix glass 8650, which requires oxidizing atmosphere during hot pressing, an additional furnace (not shown here) is available which can be inserted in the hot press. In Fig. 4 (down on the left), several composite disks are shown: In the middle, a black one (1) with C-coated fibers, then two white ones (2) whose optical and thermal properties of the fibers and the matrix glass are not adapted, and four translucent disks (3) with differently – in any case better adapted – properties. Table 3 shows an overview of the manufacturing param￾eters employed. The hot pressing temperature is mainly influenced by the transformation temperature Tg of the matrix glass. The pressure varied from 5 to 15 MPa. The results presented in this paper were all obtained in tests car￾ried out at a pressure of 5 MPa. Fig. 3. Topography of the Nextel 440-fiber, coated with 30 nm BN and 30 nm TiO2 [14] (AFM picture). Fig. 4. Principle of composites preparation. Table 3 Parameters of the composites preparation d90 of the matrix glass <70 lm Fiber volume content 8–35% Fiber direction Unidirectional Slurry Deionized water without additives Pressure 5 Mpa Temperature N-SK 4-matrix 850 C Duran-matrix 850 C 756-matrix 700 C 8650-matrix 600 C Atmosphere N-SK 4-matrix Vacuum Duran-matrix Vacuum 756-matrix Vacuum 8650-matrix Oxidizing 366 D. Hu¨lsenberg et al. / Composites: Part B 39 (2008) 362–373