27 research outputs found
A New Mechanism for the Alpha to Omega Martensitic Transformation in Pure Titanium
We propose a new direct mechanism for the pressure driven alpha to omega
martensitic transformation in pure titanium. A systematic algorithm enumerates
all possible mechanisms whose energy barriers are evaluated. A new, homogeneous
mechanism emerges with a barrier at least four times lower than other
mechanisms. This mechanism remains favorable in a simple nucleation model.Comment: 4 pages, 4 figure
Systematic pathway generation and sorting in martensitic transformations: Titanium alpha to omega
Structural phase transitions are governed by the underlying atomic
transformation mechanism; martensitic transformations can be separated into
strain and shuffle components. A systematic pathway generation and sorting
algorithm is presented and applied to the problem of the titanium alpha to
omega transformation under pressure. In this algorithm, all pathways are
constructed within a few geometric limits, and efficiently sorted by their
energy barriers. The geometry and symmetry details of the seven lowest energy
barrier pathways are given. The lack of a single simple geometric criterion for
determining the lowest energy pathway shows the necessity of atomistic studies
for pathway determination.Comment: 11 pages, 2 figure