#HOW TO READ PHASES OF TERNARY DIAGRAM SOFTWARE#

The intention is also to guide those with a different background, such as mechanical engineering, physics or chemistry, into using this cornerstone of knowledge in materials science and engineering. It aims at a readership with no or insufficient prior exposure to phase diagrams or chemical thermodynamics. However, advanced aspects in that context will also be covered.

#HOW TO READ PHASES OF TERNARY DIAGRAM SOFTWARE#

The purpose of this work is to present a primer on вЂњHow to Read and Apply Phase DiagramsвЂќ in the current environment of powerful software packages. That is exemplified in this work for metastable phase diagrams and processes such as friction stir welding, coating, and non-equilibrium вЂњScheil solidificationвЂќ. However, it is emphasized that phase diagrams are also indispensable to understand off-equilibrium processes. On the other hand, they do not include kinetic effects, for instance the nucleation undercooling and/or growth undercooling observed in practical solidification. That makes them unique for a given material system. Properly constructed phase diagrams display the phase relations at thermodynamic equilibrium state of matter. That applies to all sorts of materials, such as alloys, ceramics, semiconductors, cement, concrete etc., and to a multitude of processes, such as melting, casting, crystal growth, joining, solid-state reaction, heat treatment/phase transformation, oxidation, vapor deposition, and so on. That is why one can use phase diagrams as the starting point for materials design and process optimization by manipulating composition and processing variables to achieve the desired microstructures. Phase diagrams are the perfect road map to understand the conditions for phase formation or transformation in any material system caused by variation of temperature, composition, pressure or any other viable state variable. All of the physical and chemical properties of a material are basically governed by the type of phase(s) and, in a multiphase material, the phase assembly. Each phase is an essentially homogeneous part of the system with definite bounding surfaces (phase boundaries) and unique вЂњstructureвЂќ, such as gas, liquid, or one of the many solid crystal structures. Virtually all materials of practical interest are composed of various phases. This famous quotation coined by Sir William Hume-Rothery is a perfect guideline for any work in materials science and technology. вЂњPhase diagrams are the beginning of wisdom-not the end of itвЂќ. The embedded application examples for real material systems and various materials processes also emphasize the use of phase diagrams for the path from initial off-equilibrium state towards equilibrium. The generic approach is directly applicable for all inorganic materials, but exemplified in this concise work for a small selection of metallic systems to highlight the interdependences among the phase diagrams. Thermodynamic solidification simulation using the Scheil approximation in comparison to the equilibrium case is covered in context of multicomponent multiphase solidification and exemplified for Mg-Al-Zn alloys. The most useful concept of zero-phase fraction lines in phase diagram sections of multicomponent systems is made clear by coming back to the Cu-Ni and Mg-Al-Zn systems. The use of stable and metastable phase diagrams and appropriate choices of state variables are explained for the relevant Fe-C and Fe-C-Si systems. Application examples are directly derived from these phase diagrams of Fe, Cu-Ni, Mg-Al, and Mg-Al-Zn. Starting from the very basics it explains the reading of unary, binary and ternary phase diagrams, including liquidus projections, isothermal and vertical phase diagram sections. It is a brief guide into using this cornerstone of knowledge in materials science and engineering and offers assistance in the proper interpretation of results obtained from state-of-the-art Calphad-type thermodynamic calculations. Advanced aspects in that context are also covered. This work presents a primer on вЂњHow to Read and Apply Phase DiagramsвЂќ in the current environment of powerful thermodynamic software packages.

How to read phases of ternary diagram