Formation, structure, and crystallization of metastable quasi-crystalline Al–transition metal alloys prepared by rapid solidification

Abstract

Metastable Al₈₆Cr₁₄, Al₈₆Mn₁₄, and Al₈₆Fe₁₄ were prepared by rapid quenching from the melt at a rate of approximately 2 × 10⁶ K/s. The X-ray measurements of all three alloys show similar non-Bravais structures. Broadened diffraction peaks for the Al–Fe alloy suggest a crystallite size of about 60 Å. Thermal-analysis measurements show that all of the alloys transform into conventional crystal structures at approximately 670. The crystalline phases for the three alloys are Al₁₁Cr₂ + Al, Al₆Mn + Al, and Al₆Fe + Al. At approximately 800 K, Al–Fe undergoes the further transition Al₆Fe → Al₃Fe + Al.