Deformation behavior and failure mechanisms in particulate reinforced 6061 Al metal-matrix composites

The deformation behavior and failure mechanisms in 6061 Al alloy matrix particulate composites were examined via uniaxial tension and compression tests. The dependence of the deformation behavior on the matrix properties was studied by varying the heat treatment conditions (T4 and T6) of the matrix. The influence of the heat treatment condition on the deformation behavior of the composite was observed to be stronger than the influence of particle shape, size and volume fraction. In both tension and compression testing, composites in the T4 condition experience a larger degree of work-hardening as compared to the materials in the T6 condition. When subject to uniaxial tension, the deformation and failure behavior is strongly dependent on the relative strengths of the particles and matrix, and on the work-hardening behavior of the matrix, which is influenced by heat treatment condition. In compression, the particles merely act as obstacles to the flow of the matrix, whereas in tension they influence the failure mechanism of the composite.