Influence of superheat before quench on the structure and stability of NiP metallic glasses studied by neutron scattering techniques

The temperature dependent structure of Ni81P19 metallic glasses, rapidly quenched from melts which have undergone different heat treatments, has been investigated by small angle neutron scattering and neutron diffraction. All samples contain in the as-quenched state particles or clusters of a very wide range of sizes. These are amorphous regions of different compositions in a large composition range and/or crystallites of another Ni composition than the matrix, such as Ni3P, Ni5P2 or Ni12P5, or even “voids”. The results can be interpreted within the concept of a heterogeneous structure existing in eutectic melts in a certain temperature range. Comparison is made with results from the literature on samples from the same ribbons investigated by calorimetry as well as by fractography and Weibull analysis of mechanical properties.