This webinar will take place on Tuesday, November 25, from 1:00 p.m. to 2:00 p.m. The login link will be sent to registered participants on Tuesday morning.

Ni-Ti shape memory alloys (SMAs) are functional materials, which show thermal (one way effect – 1WE) and mechanical memory (pseudoelasticity – PE). Both effects rely on the martensitic phase transformation, which is characterized by a diffusionless transformation from austenite to martensite, between the martensite start temperature M_S and the martensite finish temperature M_F, when cooling from the high temperature regime. The reverse transformation from martensite to austenite occurs during heating from the low temperature regime, where the austenite forms between the austenite start and finish temperatures, A_S and A_F. The forward and reverse martensitic transformations can be observed in the optical and scanning electron microscope. 

The presentation focusses on NiTi, the commercially most successful shape memory alloy. Processing is briefly discussed and then a brief introduction into atomistic, thermodynamic, mechanical and microstructural aspects is given. Examples for applications are presented and recent research topics are highlighted.

Prof. Dr.-Ing. Gunther Eggeler, Ruhr-University Bochum (RUB), Chair for Materials Science, D-44780 Bochum, E-mail: gunther.eggeler@rub.de

Education: 1985 Dr.-Ing. Degree at the Friedrich-Alexander University in Erlangen (FAU, Germany); 1992 Habilitation at the Swiss Federal Institute of Technology in Lausanne (EPFL, Switzerland). Positions: 1979 -1985 Graduate Student at FAU; 1985 -1987 Post-doc at EPFL; 1987 -1990 Senior Principal Metallurgist at ERA Technology (England, UK); 1990 -1995 Research Associate at EPFL; 1995-2025 Professor for Materials Science at the Ruhr-University Bochum (RUB); since August 2025: Senior Professor for Mateirals Science at the Ruhr-University Bochum. 

Research: Elementary microstructural processes which govern plasticity and phase transformations. ≈ 500 publications. Director of two 12-year Collaborative Research Centers (funded by the German Research Association, DFG) on Shape Memory Technology (SFB 459) and on Single Crystal Ni-base Superalloys (SFB/TR 103). Teaching: Thermodynamics and kinetics, Mechanical properties, Transmission electron microscopy; > 80 graduate students, numerous master and bachelor students. 

Awards: 2005 - International Tammann Medal of the German Society for Materials (DGM); 2008 -Member of the Scientific Academy of North-Rhine Westfalia; 2008 - Bram Prakash visiting professor at the Indian Institute of Sciences (IISc) - Bangalore; 2013 Ernst Mach award of the Czech Academy of Sciences (Physical Sciences); 2013 - Hsun-Lee lecture award of the Chinese Academy of Sciences;. 2017 -

Fellow of the Japanese Society for the promotion of sciences; 2020 - Heyn commemorative medal of the DGM; 2021 - Member of the German Academy of Engineering (acatech). Visiting professor/visiting scientist (longer term stays) at: OSU Columbus (US); IISc Bangalore (India); IIT Madras (India); CEA Saclay (France); Centro Atomico de Bariloche (Argentina); University of the Balearic Islands (Spain); UCSB Santa Barbara (US); Tohoku University (Japan); University of Kyoto (Japan), Oak Ridge National Laboratory (US). Other: One (of two) presidents of the German Society of Materials (DGM). From summer 2025 on: Senior Professor at the Ruhr-University Bochum.