LSAM 2016: Interfaces and hysteresis in solid phase transformations - Sir John Ball
Thời gian: 14:00:23/08/2016 đến 17:00:25/08/2016
Địa điểm: C2-714
Báo cáo mời: Professor Sir John Ball
Tóm tắt:This is the first lecture of VIASM lecture series in applied mathematics.
Many alloys undergo phase transformations involving a change of shape of the underlying crystal lattice at a critical temperature. In order for such a phase transformation to take place, the product phase needs to be able to form a microstructure that is geometrically compatible with the parent phase. Lack of compatibility induces hysteresis, while special properties of the transformation strain allow increased geometric possibilities and thus lower hysteresis. The lectures will describe the underlying nonlinear elasticity theory and the connection of the analysis of microstructure with deep unsolved problems of the calculus of variations. They will explain how the mathematical study of compatibility has led to the recent discovery of new kinds of interfaces between phases and spectacular new ultra-low hysteresis materials.