Applied Mathematics Colloquium - Triple line formation energy

Dates

Tuesday, May 31, 2022 - 14:00 to 15:00

Speaker:   Paul Twine (Manchester University and The Open University)

Abstract:

A fundamental question in material science is how to find relationships between the microstructure and the macroscopic properties of a material. 

Polycrystalline materials consist of grains, grain boundaries and junction lines and their properties are essential to understanding the microstructure. A grain boundary is a two dimensional interface between two grains. A junction line is a one dimensional defect where three or more grain boundaries meet. The most common junction line is a triple line.  A triple line has three adjacent grains and is where three grain boundaries meet.

This presentation investigates the formation energy of triple lines in a polycrystalline material using molecular dynamics. A Gibbsian approach is used to calculate the triple line formation energy exploiting the symmetry of two closely related simulation cells. Grain boundary formation energies are always positive however this Gibbsian approach shows that triple lines can have positive or negative formation energy.