Paper number 739
CHEMICAL COMPATIBILITY BETWEEN ALUMINIUM BASE MATRICES AND LIGHT REFRACTORY CARBIDE REINFORCEMENTS |
J.C. Viala, M. Peronnet, F. Bosselet and J. Bouix
Laboratoire des Multimatériaux et Interfaces, UMR CNRS 5615, Université Lyon 1, F 69622 Villeurbanne Cedex, France
Summary | The main features of the interface chemistry of Al/B4C, Al/TiC and Al/SiC couples at temperatures up to 1000°C are presented and discussed in terms of thermodynamics, kinetics and reaction mechanism. The Al/B4C couple appears reactive whatever the temperature whereas a reactive-non reactive transition occurs at 812°C on heating for the Al/TiC couple and at 650°C on cooling for the Al/SiC couple. The reaction products are Al3BC and AlB2 or -AlB12 for the Al/B4C couple, Al4C3 and Al3Ti for Al/TiC and finally Al4C3 and dissolved silicon for Al/SiC. Whatever the couple, interaction always proceeds via a dissolution-precipitation mechanism which ends in certain instances with the passivation of the base carbide surface by a continuous Al3BC or Al4C3 layer. Some examples are given illustrating how advantage can be taken of these features for interface tailoring. |
Keywords | metal matrix, aluminium, boron carbide, titanium carbide, silicon carbide, interface, chemical reactions. |