Quantitative chemical-structure evaluation using atom probe tomography: Short-range order analysis of Fe-Al

Area of Science:

• Materials Science
• Physical Chemistry
• Metallurgy

Background:

• Short-range order (SRO) significantly influences material properties.
• Quantitative evaluation of SRO in alloys like Fe-18Al is crucial for understanding their behavior.
• Atom Probe Tomography (APT) offers high-resolution 3D atomic information.

Purpose of the Study:

• To quantitatively evaluate SRO in an Fe-18Al alloy.
• To assess the impact of limited detector efficiency and spatial resolution in APT on SRO analysis.
• To demonstrate the benefit of lattice rectification for improved SRO analysis.

Main Methods:

• Utilized atom probe tomography (APT) for 3D atomic position data acquisition.
• Calculated generalized multicomponent short-range order (GM-SRO) parameters via shell-based analysis.
• Employed simulated D03 ordered data to test the accuracy of the SRO evaluation method.

Main Results:

• Limited detector efficiency had minimal adverse effect on SRO analysis.
• Combined effects of limited detector efficiency and spatial resolution led to data appearing more randomized.
• Lattice rectification of experimental APT data significantly improved information sensitivity for GM-SRO analysis.

Conclusions:

• The study provides a quantitative assessment of SRO in Fe-18Al alloy.
• Instrumental limitations in APT can affect the apparent degree of SRO, necessitating careful data processing.
• Lattice rectification is a valuable step for enhancing the accuracy and sensitivity of SRO analysis from APT data.