Indirect material density measurement by a simple digital imaging method

This paper describes a simple solution for indirectly measuring the density of porous materials by means of a simple imaging approach. The density of these materials can hardly be determined by conventional Archimedes' principle based instruments, since the liquids penetrate inside the pores thus altering the result, while the proposed procedure requires only a simple commercial camera, is suitable for quasi-2D shapes and does not require complex a-priori camera calibration procedures. The proposed solution has been employed to estimate the density of porous magnesium samples obtained via a spark plasma sintering process. These samples, which can be characterized by either nearly full density or open interconnected porosities, often have irregular shapes as they are produced to realize tools and bio-implants of complex geometry, so that their density cannot be determined either by simple dimensional measurements or by off-the-shelf instruments.