Deformation and forging limits for a particulate-reinforced aluminum matrix composite.

摘要

Discontinuously-reinforced aluminum (DRA) matrix composites, i.e., aluminum alloys containing ceramic particles, have potential applications in the automotive industry for engine components and brake systems because of their high specific stiffness, strength and resistance to wear. Among the component fabrication processes for these composites, net shape forging is a viable potential method. Hot forging can also improve the mechanical properties of the composites in comparison to casting. One of the objectives of this research was to determine the limiting strains for a DRA matrix composite, 2014 Al/15v%Al;As part of the deformation study, it has been found that at room temperature the effective stress-strain curves were different under various stress states, i.e., uniaxial tension, equibiaxial tension (bulge) and compression tests, for this composite. The result raises a question on whether the effective stress-strain function for DRA matrix composites is independent of stress state. A possible explanation of such phenomena is offered here.;The tensile fracture modes for the composite were also examined at elevated temperatures. It was found that the deformation and fracture mechanisms were via a dislocation creep process at 300