Chapter 10. Reaction-Formed Processes for AlN/Al Ceramic Composites
- John B. Wachtman Jr.
Published Online: 28 MAR 2008
Copyright © 1994 The American Ceramic Society
Proceedings of the 18th Annual Conference on Composites and Advanced Ceramic Materials - A: Ceramic Engineering and Science Proceedings, Volume 15, Issue 4
How to Cite
Yuan, D.-W., Chengn, V.-S., Yan, R.-F. and Simkovich, G. (1994) Reaction-Formed Processes for AlN/Al Ceramic Composites, in Proceedings of the 18th Annual Conference on Composites and Advanced Ceramic Materials - A: Ceramic Engineering and Science Proceedings, Volume 15, Issue 4 (ed J. B. Wachtman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470314500.ch10
- Published Online: 28 MAR 2008
- Published Print: 1 JAN 1994
Print ISBN: 9780470375327
Online ISBN: 9780470314500
- capillary rise;
AlN/Al ceramic matrix composites have been fabricated by directed nitridation of molten binary aluminum alloys in a nitrogen-containing atmosphere. A wide range of processing parameters was used, including variations in alloy composition, temperatures, and oxidant composition. It was observed that alkaline earth elements, such as Mg, Ca, Sr and Ba, can significantly promote the nitridation reaction of Al binary alloys. An Al-3Ca alloy possessed the highest growth rate of 29.7 × 10−5 g/cm2-sec and the lowest activation energy of 5.81 KJ/mole Al at 1200°C. In comparison, the activation energy of Al-4Ba and AI-4Sr alloys in pure N2 is 45.5 and 81.8 KJ/mole Al, respectively, between 900° and 1100°C. Density, Young's modulus, hardness and fracture toughness of the resulting composite materials were determined. Composites grown from Al-4% Ba alloys were found to exhibit high Young's modulus of 170.3 GPa and Vickers hardness of 5.66 GPa.