Study On Fabrication Of Metal Matrix Composites Reinforced With High Of Si Particle

Si/Al-Zn composites and Si/Al composites were fabricated by powder metallurgy method and the pressure infiltration method in this paper. The technologic parameters such as pressure and temperature were analyzed and calculated in the fabrication process. And the microstructure was observed and analyzed. The problems of both the powder metallurgy method and the pressure infiltration method were discussed and settled. The results show that:1. Compared with the traditional powder metallurgy method, Si/Al-Zn composites were fabricated by adding zinc on the Al-Si billet in the sintering process. In this process, Si-Al billet was sinteringed by Si particles and Al particles. And Si-Al billet was infiltrated by Zn liquids.2. On the fabrication process of Si/Al-Zn composites, the effects of solid sintering and infiltration process are different. The analysis of microstructure shows that infiltration process is leading. It is analyzed that the bad wettability between silicon and zinc lead to some holes exist in Si/Al-Zn composites.3. It is researched that the pressure infiltration method can settle the problem of wettability between strengthened particles and metal matrix materials. Si/Al composites were fabricated by this technique. The rigidity of Si/Al composites was measured and the CTE of Si/Al composites was calculatedin theory.4. By optical microscopy, XRD and SEM methods, the analysis of microstructure showed that the distribution of Si particles in the Al matrix was symmetrical without aural protect. And Oxide was not found in Si/Al composites. So the pressure infiltration method is feasible in preparing Si/Al composites.5. The content of silicon was 30wt%, 50wt%, 100wt% in the preform respectively. To the different content of Si in the preform, the distribution of Si particles in the Al matrix was all uniform. If the perform wasn' t distortion, the content of Si particle and Al matrix can be adjusted freely in the process of the pressure infiltration method.6. After the analyze of infiltration dynamics in theory, the numerical value of capillarity pressure and viscidity resistance can be calculated. Compared pressure in theory with pressure in practice, it was found that they were not same because the calculating model was idealized and the effect of atmosphere resistance was ignored.