On the segregation of Re at dislocations in the {\gamma}' phase of Ni-based single crystal superalloys

TL;DR

This study investigates how Re and Mo atoms segregate along dislocations within { extbackslash gamma}' precipitates in Ni-based superalloys after creep deformation, revealing mechanisms that could inform better alloy design.

Contribution

It provides new evidence of Re and Mo segregation at dislocations inside { extbackslash gamma}' phases and explains the underlying diffusion mechanisms involved.

Findings

Re and Mo segregate up to 2.6 at.% and 1 at.% respectively.

Segregation occurs along dislocation cores within { extbackslash gamma}' precipitates.

Understanding these mechanisms can guide improved alloy development.

Abstract

We report evidence of Re and Mo segregation (up to 2.6 at.% and 1 at.%) along with Cr and Co to the dislocations inside of {\gamma}' precipitates in a second generation Ni-based single crystal superalloy, after creep deformation at 750{\deg}C under an applied stress of 800 MPa. The observed segregation effects can be rationalized through bridging the solute partitioning behavior across the {\gamma}/{\gamma}' interface and the pipe diffusion mechanism along the core of the dislocation line. This understanding can provide new insights enabling improved alloy design.