Abstract

Solid solutions are common in metallurgy – like ordinary liquid solutions, their free energy is less sensitive to variations in chemical composition unlike compounds which tend to have fixed ratios of solutes. Metallic solid solutions are sometimes created without melting, because it then becomes possible to make exotic compositions without the problems of chemical segregation or the limits of solubility. The process involves the attrition together of the chemical components, for example in a ball mill, until mixing is complete. In this talk I will address whether this is in fact a true scenario considering both experimental data at an atomic resolution and theory. The latter takes the form of a new treatment of the thermodynamics of particle mixtures in which the particles are no longer atoms. Some novel phenomena emerge, which I hope will stimulate new thinking.