Ceramic Composites Derived from Polysiloxane/Al/Nb by AFCOP Process

Abstract:

In this work, ceramic matrix composites (CMC) were prepared by AFCOP process, using a polysiloxane network filled with metallic niobium and aluminum powders as active fillers. The liquid polysiloxane precursor was loaded with a suitable polymer/filler ratio in relation to stoichiometric Nb : C and Al : O molar ratios. Changing Al for a-Al2O3, which acted as an inert filler, non-stoichiometric conditions were obtained. The mixtures were blended, uniaxially warm pressed, and pyrolysed in flowing argon at 800, 1000 and 1200 °C. Thermogravimetry was used to follow the weight changes during the pyrolysis process. X-ray diffraction was used to identify the formation of new crystalline phases, such as Al2O3, NbC, Nb2C and Al3Nb in the composites. Sintered specimens were also characterized by SEM and EDS. The results indicated good potential for this system to obtain multiphasic composite material in the Al-Nb system at lower temperatures.

• Periodical: Materials Science Forum (Volumes 498-499)
• Pages: 375-380
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.498-499.375
• Online since: November 2005
• Authors: Marco Antônio Schiavon, I.V.P. Yoshida, José Carlos Bressiani, Wilson Acchar
• Keywords: AFCOP, Ceramic Matrix Composite (CMC), Polymer Pyrolysis, Polysiloxane, Pre-Ceramic Polymer

References

[1] P. Greil, Adv. Eng. Mater. 2 (2000), p.339.

[2] Q. Wei, E Pippel, J. Woltersdorf, M. Scheffler, P. Greil, Mater. Chem. and Phys. 73 (2002), p.281.

[3] P. Greil, J. Am. Ceram. Soc., 78 (1995), p.835.

[4] M. A. Schiavon, E. Radovanovic, I. V. P. Yoshida, Powder Technol. 123 (2002), p.232.

[5] O. Dernovsek, J. C. Bressiani, A. H. A. Bressiani, W. Acchar, P. Greil, J. Mater. Sci. 35 (2000), p.2201.

DOI: 10.1023/a:1004766607619

[6] M. A. Schiavon, L. C. Pardini, I. V. P. Yoshida, Key Eng. Mater. 189 (2001), p.48.

[7] 10. M. A. Schiavon, S. A. U. Redondo, S. R. O. Pina, I. V. P. Yoshida, J. Non-Cryst. Solids 304 (2002), p.92.

[8] Powder Diffraction File Search Manual, Joint Committee on Powder Diffraction Standarts, Swarthmore, (1973).

[9] T. Michalet, M. Parlier, F. Beclin, R. Duclos, J. Crampon, J. Eur. Ceram. Soc. 22 (2002), p.143.