Estimation Procedure for Volume Fraction of Minor and Rod Phase Aligned Unidirectionally in a Matrix

Knowing the volume fraction of a minor phase in a composite material is important for characterizing its mechanical properties. Assuming that a rod-like phase with a constant diameter is aligned but dispersed randomly in a matrix, a mathematical model for estimating the volume fraction of a rod-like phase has been developed. This model predicts how many rods are required for an accurate estimation of volume fraction. One of the effective features of this model is that the real dimensions do not need to be considered due to the similarity of their shape. According to this model, it is sufficient to measure the area that includes at least 20 rods to estimate an accurate value for volume fraction. This prediction was confirmed by measuring a unidirectionally solidified Sn-Cu eutectic alloy system. [doi:10.2320/matertrans.M2014424]