Short range ordering of heavy element columns in nickel based superalloys

TL;DR

This study reveals that heavy elements in nickel-based superalloys tend to form short-range ordered stripes along specific crystallographic directions, enhancing mechanical performance.

Contribution

It uncovers the short-range ordering of heavy-element columns in superalloys and links this structure to improved mechanical properties.

Findings

Heavy-element columns align along <100> and <110> directions.

Short-range ordering forms 1-2 nm stripes.

Ordering benefits mechanical performance.

Abstract

To obtain comprehensive performance, heavy elements were added into superalloys for solid solution hardening. In this article, it is found by scanning transmission electron microscope observation that rather than distribute randomly heavy-atom columns prefer to align along <100> and <110> direction and form a short-range ordering with the heavy-element stripes 1-2 nm in length. Due to the strong bonding strength between the refractory elements and Ni atoms, this short-range ordering will be beneficial to the mechanical performances.