压力浸渍过程中P-55纤维和铝合金界面反应的控制

 压力浸渍法是制造金属基复合材料方便而廉价的方法。在这种工艺过程中,能独立控制纤维预制件温度T_p、熔融金属温度T_m、浸渍压力P和冷却速度等重要工艺参数。在金属基复合材料中,纤维与基体间的界面反应使纤维强度下降,复合材料性能恶化,从而限制了复合材料的广泛使用。本文主要研究如何控制无涂层的P-55纤维与1100Al和Al-0.34％Ti合金之间的界面反应,讨论压力浸渍法工艺参数对P55/Al和P55/Al-Ti复合材料组织、性能的影响。结果表明:通过控制工艺参数来缩短纤维与熔融金属铝之间的接触时间和在基体中加入钛元素以降低碳在熔融铝中的活性可以制造出高性能的复合材料。

CONTROL OF INTERFACE REACTIONS BETWEEN P-55 FIBERS AND ALUMINIUM ALLOY MATRICES DURING PRESSURE INFILTRATION PROCESSING

The pressure infiltration process is a convenient and inexpensive method for manufacturing cast metal matrix composities. Inherent in the process is the ability to independently control the most important processing parameters such as fiber preform temperature TD, melt temperature T'm infiltration pressure P, and cooling rate, (or solidification time).A deterrent to the use of these materials for structural applications where high specific strength and modulus properties are important are the interfacial reactions between fiber and the matrix which degrade the fiber strength and hence, the com-posity strength. This investigation is primarily concrened with controlling interfacial reactions between P-55 graphite fibers and 1100A1 and Al-0.34%Ti alloys. The effects of processing parameters on these three systems were evaluated. This evaluation included optical and TKM metallography, SEM fraotography as well as mechanical property testing of composite castings and fibers leached from composite castings. The results of these evaluations show that sound composites with high mechanical properties can be produced by at least two routs: (1)control of processing parameters so as to minimize high temperature exposure of the fiber surfaces to molten metal, (2) alloying the matrix with Sior Ti to reduce the activity of carbon in the molten matrix.