Effect of fiber orientation on mechanical properties of 2D-C_f/Al composites by liquid-solid extrusion following Vacuum infiltration technique

Through the method of fiber lamination, carbon fiber preforms with different orientation angles of 30°, 45°, 60° and 90° were prepared, and 2D-C_f/Al composites were fabricated by liquid-solid extrusion following the vacuum infiltration technique (LSEVI). Through mechanical properties test of the above composites, it showed that ultimate tensile strength (UTS) of the obtained C_f/Al composite was improved more than that of the matrix alloy. It was found that the volume fraction of four kinds of preform was about 45%. Fibers were arranged according to a certain direction, and this was very helpful in improving the performances of composites. In the preparation process, squeeze pressure was far greater than theoretical calculated value, and this was because many infiltration factors had been simplified and ignored in the theoretical calculation model. Infiltration of composites was sufficient and uniform and obvious defects could not be found. Tensile fracture was uneven, indicating that fibers played the reinforced role effectively, which also improved the properties of the composites greatly. Meanwhile, the increased rates of composites' UTS with different angles had large differences. When the angles were 45° and 90°, the increased rates were 112.5% and 63.9%, respectively. Through theoretical analysis and experimental comparison, it was concluded that the total fiber bearing capacities were the key dominant factor.