Predicting the size- and temperature-dependent shapes of precipitates in Al–Zn alloys

摘要: Abstract We study theoretically the size versus shape temperature relation of precipitates in Al–Zn via quantum-mechanical first-principles simulations. Our parameter-free model, based on a mixed-space cluster expansion, allows prediction experimentally observed and dependences precipitate shape. find that aging experiments can be explained terms equilibrium shapes. The change from nearly spherical to more ellipsoidal/hexagonal with increasing decreasing temperature. They always flatten [111] direction, which interpreted as consequence mechanical instability face-centered cubic Zn when rhombohedrally distorted along strong anisotropy chemical energy. excellent agreement between experiment theory shows our model used quantitatively predict shapes sizes.