A model of liquid metals and its relation to the solidification process

X-ray analysis shows that a liquid is build up of clusters of atoms with a certain number of nearest neighbours. The X-ray analysis shows that 8-11 nearest neighbours surround each atom. Each cluster has a crystal-like structure. Between the clusters there are some free atoms and free electrons. The enthalpy of fusion is according to Richard's rule around the gas constant times the temperature of melting and the heat capacity in the liquid state is normally constant and for some metals lower than that in the solid state. For metals with low melting points it will decrease further with increasing temperature. This behaviour of the metals can be explained by the use of statistical mechanics and by assuming that the clusters, observed by X-ray analysis are rotating around a centre of its mass. The cluster model is applied to explain the diffusion rate in liquid metals. The effect of the experimental set upon measurements of diffusion constants is discussed as well as its effect on crystal growth. (c) 2005 Elsevier B.V. All rights reserved.