Preliminary analysis of aluminum matrix compositions for composites reinforcement with carbon fibers

In the liquid phase methods of obtaining the composites, one of important conditions is contact between liquid metal and the reinforcement. In the system of aluminum and carbon fiber, proper connection between liquid and the fibers depends not only on the wetting conditions but also on the reactivity of the components. In the processes of infiltration, one of the factors conducive to such a connection is the chemical composition of the alloy matrix. The composition of the alloy also decides on technological properties such as castability and shrinkage. The paper presents the results of modification AlSi9Cu(Fe) and AlSi9Mn base alloy with addition of magnesium and strontium. The scope of researches includes analysis of the structure alloys before and after modification and results of the compared metal flow in the gravity casting to graphite mold. The mold applied in the study allows the analysis of metal flow in ducts of varying cross section. In case of modified alloy AlSi9Cu(Fe) + 1% Mg + 0.03%Sr was observed a slight decrease of fluidity. While in the case of alloy AlSi9Mn +1% Mg +0.03%Sr length of filled increased comparing to similar beams on base alloy. The aim of modifying the chemical composition of the base alloy was to improve wettability in the Al/CF system during the infiltration process. In the case of an alloy AlSi9Cu(Fe), intended for use in the high pressure die casting (HPDC) process, small change of fluidity has no significant meaning. While for AlSi9Mn the effect of improving the melt fluidity is beneficial from the standpoint of technology GPI. This paper presents preliminary results on modification of aluminum alloys applied for pressure infiltration in the carbon textiles. The scope of this study includes an analysis of the microstructure of modified alloys and comparative evaluation the casting properties. The research was carried out with selected AlSi9Cu(Fe) and AlSi9Mn alloys modified by addition of 1% Mg and 0.03% Sr.