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The role of CALPHAD in the science of materials
- Date: 24.05.2011
- Time: 5:00 p.m.
- Place: CALPHAD XL Conference, Rio de Janeiro, Brazil, 22.-27.05.2011
CALPHAD was born as a method to calculate phase diagrams from modeled Gibbs energies. These models developed so soaked in experimental facts that not only phase diagrams but other quantities, like Cp curves, calculated using CALPHAD, are sometimes mistaken as they would be the genuine experiments. These calculations became so associate to CALPHAD that sometimes the method is mistaken as a computer code. An outsider looking briefly to the word can erroneous infer that CALPHAD is a code that calculates experimental facts. This misunderstanding can lead to erroneous and dangerous conclusions: no experiments are need anymore, no new models are need, all is already in CALPHAD. However, independently of the way the word CALPHAD is understood, there is an irrefutable evidence: CALPHAD is part of the needs in Materials development. One would like to have a method that would predict materials behavior like the idealized CALPHAD. Density functional theory can help in that point. However, like experimental values, the observable quantities predicted by the theory are discrete and models are still necessary to connect them. The generalized CALPHAD concept is a dynamical network of consistent information that permeates scales and adapts itself as a whole by the demands of the application in agreement to new theoretical achievements. This generalized CALPHAD should be constructed (SAPIENS project is a part of it, see Ursula Kattner and Mauro Palumbo’s lectures) and taught in materials science courses to create a connected way of thinking, independently of discipline, scale or technique. In this lecture some examples will illustrate that even if CALPHAD is just a part of alloys design it is a decisive one.
Acknowledgement: ThyssenKrupp AG, Salzgitter Mannesmann Forschung GmbH, Robert Bosch GmbH, Bayer Materials Science AG, Bayer Technology Services GmbH, Benteler Stahl/Rohr AG, the state of North Rhine-Westphalia and the European Commission in the framework of the European Regional Development Fund (ERDF).