The progress of solid-state phase transformations can generally be subdivided into three overlapping mechanisms: nucleation, growth and impingement. These can be modelled separately if hard impingement prevails. On that basis, an overview has been given of recent numerical and analytical methods for determination of the kinetic parameters of a transformation. The treatment focuses on both isothermally and isochronally conducted transformations. To extend the range of transformations that can be described analytically, a number of more or less empirical submodels, which are compatible with experimental results, has been included in the discussion. It has been shown that powerful, flexible, analytical models are possible, once the concept of time or temperature dependent growth exponent and effective activation energy, in agreement with the existing experimental observations, has been adopted. An explicit (numerical) procedure to deduce the operating kinetic processes from experimental transformation-rate data, on the basis of different nucleation, growth and hard impingement mechanisms, has been demonstrated. Without recourse to any specific kinetic model, simple recipes have been given for the determination of the growth exponent and the effective activation energy from the experimental transformation-rate data.

An overview of the thermophysical properties of segregating and demixing liquid binary alloys is presented encompassing the simple approaches that are commonly used by physicists, chemists and metallurgists in general. The various experimental and theoretical information available for such systems are put together to establish a respectable understanding between the experimental results, theoretical approaches and the empirical models.The key to understanding is the deviation that the properties exhibit from Raoult's law and the marked change in the liquid phase as a function of composition, temperature and pressure. The characteristic behaviour is ascribed to an outcome of the interplay of the energetic and structural re-adjustment of the constituent elements on mixing. After summarizing the experimental technique and some results, a comprehensive microscopic approach, based on statistical, electronic and hard sphere-like theory, is undertaken to further the understanding of the origin of the intriguing processes that are associated with the immiscible and phase-separating liquid alloys. We conclude by providing a brief account of the kinetic aspects of phase separation with some intended industrial applications.

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