Relationship between Compressive Strength and Fractal Dimension of Pore Structure

Two kinds of stainless steel powders, having spherical shape and irregular one with the particle sizes from 38 μm to 150 μm were used to produce porous metal materials, the specimens were sintered at 1250 °C for 2 h in vacuum. Their porosities and compressive strength were tested using Archimedes' principle and a computer controlled universal testing machine, respectively. Furthermore, the microstructures were observed by an optical microscope. In addition, the fractal theory was used to investigate the fractal dimension of the pore structure and analyze the relation ship between the compressive strength, the porosity and the fractal dimension. The results show that the fractal dimension increases gradually with increasing of the porosity. The relation ship between the fractal dimension and the porosity can be expressed using the Boltzmann model. The compressive strength and the fractal dimension can be presented by the exponential model.