Microstructure and mechanical properties of porous cast aluminium composite

The influence of the microstructural parameters of porous cast and strained aluminium composite on mechanical properties had been examined. A high purity aluminium (99.97%) was used as the matrix material. The pore volume fraction Vp was at the level of 52-54%. The mean pore size and the mean free path in the matrix varied in a wide range from 232 to 688 μm and from 346 to 1023 μm, respectively. Tensile strength of the porous cast aluminium was at a constant level of 20 MPa, and logarithmic strain increases from 4% to 10% with the increase of the mean free path in the matrix. It was shown that the dependence of pore volume fraction and tensile strength on the strain degree A had the same character. The minimum pore volume fraction and maximum tensile strength were observed in the range A > 0-5-0-8. Dependence of tensile strength on pore volume fraction for strained porous aluminium composites may be expressed as a function of porosity by a simple law of mixtures.