Enhancing Ω Phase Thermal Stability in Al Alloys through Interstitial Ordering.

Area of Science:

• Materials Science
• Metallurgy
• Computational Materials Science

Background:

• Scandium (Sc) addition to aluminum alloys improves thermal stability by forming ordered interstitial phases.
• The high cost and rarity of Scandium necessitate exploring alternative elements for similar effects.

Purpose of the Study:

• To investigate the electronic-level mechanisms behind Scandium's enhancement of thermal stability in aluminum alloys.
• To identify other elements capable of improving thermal stability through interstitial ordering in aluminum alloys.

Main Methods:

• Utilizing first-principles calculations to simulate and analyze atomic interactions and electronic structures.
• Performing a comprehensive computational screening of elements across the periodic table.

Main Results:

• Scandium's interstitial ordering in the Ω phase of aluminum alloys is confirmed to significantly boost thermal stability.
• Several other elements, including Lithium (Li), Calcium (Ca), Strontium (Sr), Samarium (Sm), Cerium (Ce), and Yttrium (Y), were identified as potential candidates for enhancing thermal stability via interstitial ordering.

Conclusions:

• The study elucidates the fundamental electronic factors governing interstitial ordering and thermal stability enhancement.
• Identified elements offer promising avenues for developing cost-effective, thermally stable aluminum alloys.