Room temperature deformation in the Fe$_7$Mo$_6$ $\mu$-Phase

TL;DR

This study investigates the room temperature deformation mechanisms of the Fe7Mo6 μ-phase using microcompression, nanoindentation, and microscopy, revealing slip on basal and prismatic planes and associated hardening effects.

Contribution

It provides the first detailed analysis of the intrinsic deformation mechanisms of Fe7Mo6 μ-phase at room temperature, including slip systems and defect interactions.

Findings

Slip occurs mainly on basal and prismatic planes.

Decohesion observed on prismatic planes with high defect density.

Pronounced hardening linked to slip interactions and pre-existing defects.

Abstract

The role of TCP phases in deformation of superalloys and steels is still not fully resolved. In particular, the intrinsic deformation mechanisms of these phases are largely unknown including the active slip systems in most of these complex crystal structures. Here, we present a first detailed investigation of the mechanical properties of the Fe7Mo6 {\mu}-phase at room temperature using microcompression and nanoindentation with statistical EBSD-assisted slip trace analysis and TEM imaging. Slip occurs predominantly on the basal and prismatic planes, resulting also in decohesion on prismatic planes with high defect density. The correlation of the deformation structures and measured hardness reveals pronounced hardening where interaction of slip planes occurs and prevalent deformation at pre-existing defects.