The distribution of intervariant crystallographic planes in a lath martensite using five macroscopic parameters

Abstract

Electron backscatter diffraction analysis was employed to compute the closest orientation relationship and the distribution of intervariant boundary character in a lath martensitic microstructure. The misorientations were close to the Kurdjumov–Sachs orientation relationship. The intervariant crystallographic plane distribution exhibited a relatively high anisotropy with a tendency for the lath interfaces to terminate on (110) planes. This results from the crystallographic constraints associated with the shear transformation rather than a low energy interface configuration. The lath martensite habit plane was determined to be mostly (110) or near (110). The relative populations of boundaries with [111] and [110] misorientations were greater than other high index misorientations, mostly characterized as (110) symmetric tilt and (110) twist boundary types, respectively. Analysis with homology metrics of the connectivity in the lath martensitic microstructure revealed the connectivity dominated by population of misorientation angle and boundary plane type.