Mechanical properties of rapidly solidified Ni5Ge3 intermetallic

Abstract

The congruently melting, single phase, intermetallic Ni5Ge3 has been subject to rapid solidification via drop-tube processing wherein powders with diameters between 850–150 μm are produced. At these cooling rates (850–150 μm diameter particles, 700–7800 K s−1) the dominant solidification morphology, revealed after etching, is that of isolated plate and lath microstructure in an otherwise featureless matrix. Selected area diffraction analysis in the TEM reveals the plate and lath are a disordered variant of ε-Ni5Ge3, whilst the featureless matrix is the ordered variant of the same compound. Microvicker hardness test result shows that mechanical properties improve with decreasing the particle size from 850 to 150 μm as a consequence of increasing the cooling rate.