The fcc-bcc crystallographic orientation relationship in AlxCoCrFeNi high-entropy alloys

• Ordering exists in the Al-Co-Cr-Fe-Ni High Entropy Alloys.
• Two different types of crystallographic-orientation relationship between the ordered phases and matrix were found.
• Nano-scaled bcc phase is observed in Al0.3CoCrFeNi, homogeneously distributed in the fcc matrix.

This paper concentrates on the crystallographic-orientation relationship between the various phases in the Al-Co-Cr-Fe-Ni high-entropy alloys. Two types of orientation relationships of bcc phases (some with ordered B2 structures) and fcc matrix were observed in Al0.5CoCrFeNi and Al0.7CoCrFeNi alloys at room temperature: (1 −1 0)bcc//(200)fcc, [001]bcc//[001]fcc, (b) (1 −1 1)B2//(2−2 0)fcc, [011]B2//[112]fcc.