Assessment of effects of aluminum solid solution decomposition on geometric structure of Al-Sn-Zn isobar phase diagram

Abstract

Three-dimensional (3D) computer model of the Al-Sn-Zn isobaric phase diagram is presented. It is shown that the T-x-y diagram consists of 64 surfaces and 25 phase regions. Features of Al-Zn binary system phase diagram related to decomposition of aluminum solid solution and its influence on geometric structure of liquidus and solidus surfaces in the ternary system, formed by this binary system and tin, are considered. Critical analysis of the published data was carried out and errors in visualization of those fragments of the Al-Zn T-x diagram, in which phase regions are formed with the participation of new aluminum solid solutions, appeared after the decomposition of the initial solid solution, are discussed. To design this 3D model, literary data were used, and the assessment of its quality is based on isopleths and isothermal sections from the same primary sources.