Nondestructive Evaluation of the Dynamic Elastic Moduli of Porous Iron Compacts

The effect of cold compaction and sintering of spherical iron powder on the dynamic elastic moduli of the partially densified material was studied. It was found that the elastic moduli of porous iron depend not only on density but also on the processing route that is followed. It was argued and demonstrated that the longitudinal sound velocity is more appropriate than density, as a parameter for quantitative nondestructive evaluation of the elastic moduli of porous iron. A general form of the dependence between the normalized elastic modulus M* and the normalized longitudinal sound wave velocity VL* was put forward: M* ≅(αVL*3 + βVL*2) C (v), where α and β are constants and C (v) is a function of the Poisson's ratio. This dependence was verified for the normalized bulk and shear moduli of porous iron compacts with data points from the literature.