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.