Quantifying short-range order using atom probe tomography

Area of Science:

• Materials Science
• Metallurgy
• Computational Materials Science

Background:

• Medium- and high-entropy alloys offer exceptional strength and ductility.
• Short-range order (SRO) is predicted computationally but challenging to measure experimentally.
• Quantifying SRO is crucial for understanding its impact on alloy properties.

Purpose of the Study:

• To develop a robust method for measuring SRO in alloys using atom probe tomography.
• To investigate the influence of heat treatment on SRO in CoCrNi alloys.
• To enable accurate computational modeling of SRO effects.

Main Methods:

• Utilized atom probe tomography (APT) to quantify species-specific SRO.
• Developed an approach to balance APT limitations with SRO threshold values.
• Applied the method to a CoCrNi alloy subjected to various heat treatments.

Main Results:

• Successfully measured SRO changes induced by heat treatments in CoCrNi.
• Established regimes where atomistic neighborhood information is preserved in APT.
• Generated experimental SRO data for validating computational models.

Conclusions:

• The developed APT approach provides a reliable way to measure SRO.
• Accurate SRO quantification advances the understanding of alloy behavior.
• This method facilitates the design of advanced medium- and high-entropy alloys.