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The superplastic characteristics of a 15% (volume fraction) SiCp (14 μm) /6A02A1 composite, fabricated by stirring casting and cold-rolling after extrusion with a low extrusion ratio of 10:1 and hot-rolling, were investigated. The composite exhibits a tensile elongation of 250% at an initial strain rate of 8.9 ×10-4 s-1 and at 833 K where an appropriate amount of liquid phase is presented in the composite. The superplastic deformation is uniform and the strain hardening exponent γis as high as 1.6. The fracture surface is intergranual and the superplastic deformation mechanism of the composite is considered to be grain boundary (interface) sliding accommodated by an appropriate amount of liquid phase.
The superplastic characteristics of a 15% (volume fraction) SiCp (14 μm) / 6A02A1 composite, fabricated by stirring casting and cold-rolling after extrusion with a low extrusion ratio of 10: 1 and hot-rolling, were investigated. a tensile elongation of 250% at an initial strain rate of 8.9 × 10 -4 s -1 and at 833 K where an appropriate amount of liquid phase is presented in the composite. The superplastic deformation is uniform and the strain hardening exponent γis as high as 1.6. The fracture surface is intergranual and the superplastic deformation mechanism of the composite is considered to be grain boundary (interface) sliding accommodated by an appropriate amount of liquid phase.