Välkommen till Institutionen för Materialvetenskap (MSE). Vi ansvarar för forskning och undervisning inom ett område som omfattar allt från konstruktionsmaterial till avancerade material. Som exempel på olika material kan nämnas aluminiumlegeringar, rostfritt stål, verktygsstål, högtemperaturmaterial, zirkoniumlegeringar, kompositmaterial, högtemperatursupraledare, magnetostriktiva material och minnesmetaller. Undervisningen omfattar grundläggande kurser i materialvetenskap men också avancerade kurser i fasomvandlingar, termodynamik, mekaniska egenskaper, keramiska material, korrosion, legeringsdesign och kurser i materialval. Institutionen är medlem av "Scientific Group Thermodata Europe" (SGTE)
Plasticity of Metals through Quantum Glasses
Scientists at the Applied Materials Physics Division develop a new theory for plasticity of face-centered cubic metals.
After release, an elongated steel coil spring or rubber return to their initial shape - they show elastic behavior. A bended fork or a pressed car body may also recover the original form if the strain level is small. At large strains, however, most materials will undergo a shape change, which is commonly named plastic deformation. In the elastic case the chemical bonds connecting the atomic network are merely tilted or stretched, whereas during the latter plastic process thousands of bonds break and re-form. More than three centuries ago, Hooke formulated his famous law describing the elastic regime. According to Hooke’s law, for a given stress level the degree of deformation is determined by the material’s stiffness constant characterizing the strength of the chemical bonds. A similar simple relationship between strain and stress valid within the plastic regime seemed unattainable.
Scientists at the Applied Materials Physics Division of the Materials Science and Engineering Department, KTH, in collaboration with their colleagues at Pohang University of Science and Technology (POSTECH) in Korea, have made an important step towards finding a unified solution to the above problem. The new transparent theory for plasticity connects the material’s response upon mechanical load to the intrinsic material properties. Using molecular dynamics simulations, researchers addressed the grain orientation effect on the deformation modes of face-centered cubic metals. They derived a key parameter that sufficiently identifies the activation of various plastic deformation modes. This finding leads to the simple deformation mode diagram as shown in the figure, which fully specifies the potential diversity of metals. The Swedish-Korean joint effort also identifies easy means to access these atomic-level parameters and to employ them in the design of novel alloys.
The research was carried out by doctoral student Minho Jo and Professors Yang Mo Koo and Se Kyun Kwon (Graduate Institute of Ferrous Technology, POSTECH), Professor Byeong-Joo Lee (Department of Materials Science and Engineering, POSTECH) and KTH Professors Börje Johansson and Levente Vitos, and is being published in the journal Proceedings of the National Academy of Sciences of the United States of America (PNAS). For more details see http://www.pnas.org/content/early/2014/04/18/1400786111.abstract.
Professor Zi-Kui Liu will lead a Hero-m seminar at MSE June 18
Professor Zi-Kui Liu at Penn State University, US, will be the recipient of the 2014 J. Willard Gibbs Phase Equilibria Award.
Zi-Kui Liu holds a PhD from the Department of Materials Science and Engineering 1992 with prof John Ågren as supervisor. Professor Liu will visit KTH in June and give a Hero-m seminar Tuesday June 18th at 2 PM.