Mechanical Properties of Interpenetrating Graphite/2024AI Composites Produced by Improved Squeeze Exhaust Casting

摘要

The graphite/2024Al composites have been fabricated by improved Squeeze Exhaust Casting (SQEC) method. Two kinds of graphite preforms with porosities of 13% and 17% respectively were infiltrated with 2024A1 (Al-5Cu-2Mg) alloy under the pressure of 73MPa. The disadvantages of traditional Squeeze Casting (SQC) were avoided and the distribution of aluminum alloy appeared homogenous 3D network in the composites. Flexural strength and Young's modulus were determined at room temperature. Compared to graphite preform, the composites exhibited a significant enhancement of mechanical properties. The flexural strength and Young's modulus of X-Y direction of G186/2024A1 composites increased from 38.6MPa to 99.7MPa and from l0.lGPa to 19.7GPa, respectively. The fracture mechanism of the composites was discussed on the basis of fracture surfaces.