Reactive infiltration of porous graphite by NiSi alloys

Infiltration of reactive NiSi alloys into porous graphite preforms is studied following in situ the variation with time of the volume of a droplet placed on the porous substrate. The shape and depth of the infiltration zone as well as the degree of transformation of carbon to silicon carbide are determined by post-mortem characterizations by scanning electron microscopy and image analysis. Experiments are performed by varying the temperature, the mole fraction of Si in the alloy and the infiltration time. The results are used to determine the process governing reactive infiltration.