| Infiltration process of fiber reinforced magnesium aluminium matrix composites made by liquid infiltration was mainly studied in the paper. Because the magnesium liquid doesn't wet the carbon fiber better, in order to improve the wettability, we can adopt heat treatment and washing method taking out the film of the fiber by experiment. And we can obtain the Al2O3 sol-gel, and the sol-gel can coat on carbon fiber. The better result was obtained by the high temperature surface treatment of carbon fiber under the atmosphere of nitrogen. The wettability between fibers and liquid metal was improved by coating Al2O3 sol-gel, and we find a new method to obtain the MMCs.The infiltration kinetics of liquid metal into fibers wastheoretically analyzed and simulated on the basis of Darcy law and the assumptions that the porous fiber was treated as bundles of capillaries and liquid penetrating the fiber was considered to be laminar. The results showed that as for the unwetting system, the liquid infiltration could be possible only when the critical infiltration pressure which was related with the surface tension of liquid metal, fiber volume fraction and the gas counterpressure was reached.In the latter part of this paper, the corrosion behavior of C/Mg composites in the solution of 3.5%NaCl , 0.05mol/L diluted hydrogen chloride and 1% Na2CO3 was studied. The experiment indicated that C/Mg composites had a better erosion resistance in 1% Na2CO3 than in the solution of 3.5%NaCl and in 0.05mol/L diluted hydrogen chloride. There was a difference impact of heat treatment on their corrosion resistance.
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