Advances in Chemical Engineering and Science, 2021, 11, 105-140 https://www.scirp.org/journal/aces ISSN Online: 2160-0406 ISSN Print: 2160-0392 DOI: 10.4236/aces.2021.111008 Jan. 29, 2021 105 Advances in Chemical Engineering and Science Nanostage Alloying of Metals in Liquid Phase Deblina Roy 1 , Tarasankar Pal 2 * 1 Department of Chemistry, National Institute of Technology, Rourkela, Odisha, India 2 Department of Chemical Sciences, Auckland Park Kingsway Campus, University of Johannesburg, Johannesburg, South Africa Abstract Alloying of metals is known from antiquity. Alloy making i.e., homogenizing metals started in a “hit-or-miss” way. The 1 st alloy from copper (Cu) and tin (Sn) was produced around 2500 BC and from then Bronze Age began. Sub- sequently iron (Fe) age started after the Bronze Age. Aluminium (Al) alloying was discovered much later because pure Al could not be recovered easily even though Al is the most abundant metal in the earth’s crust. Refining of Al is a very difficult job because of its strong affinity towards oxygen. To ease alloy- ing, melting points (mp) of the individual constituents and reactivity of metal towards oxygen were the hurdles. Now understanding the thermodynamics of metal mixing has paved alloying. Periodic properties of elements concerning size, electronegativity, crystal structure, valency, lattice spacing, etc. are con- sidered for alloying. In this feature article, more emphasis is given to Hume-Rothery rules in which the necessary parameters for alloying have been illustrated. Importantly standard electrode potential (E 0 ) values, eutec- tic, phase diagram, size-related strain in metals, etc. have been looked into in the present discussion. One elegant example is Sn-Pb alloy, known as soft solder. Soft solder was in use for many years to connect metals and in electric circuitry. Low melting, flowability, and conductivity of soft solder had placed Sn-Pb alloy a unique position in industries, laboratories and even in cottage industries. However, toxic Pb volatilizes during soldering and hence soft solder is banned almost in all countries. We felt the need for a viable alterna- tive to obtain soldering material and then silver (Ag) based highly conduct- ing, an eco-friendly alloy of Sn resulted in from a high boiling liquid. The discovery engenders not only a new conducting soldering alloy but also a new concept of melting metals together. Furthermore, new ideas of alloying have been generalized at their nanostages from a suitable high boiling solvent. Keywords Alloy, Nanoparticles, Hume-Rothery Rules, Oriented Attachment, Ostwald Ripening, Digestive Ripening, Galvanic Replacement Reaction, Kirkendall How to cite this paper: Roy, D. and Pal, T. (2021) Nanostage Alloying of Metals in Liquid Phase. Advances in Chemical Engineering and Science, 11, 105-140. https://doi.org/10.4236/aces.2021.111008 Received: December 25, 2020 Accepted: January 26, 2021 Published: January 29, 2021 Copyright © 2021 by author(s) and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY 4.0). http://creativecommons.org/licenses/by/4.0/ Open Access