High-Ni Al-Ni-Co decagonal phase

摘要

Quasiperiodic decagonal (D) phases have been observed in a number of alloy systems, but detailed investigations of their structure and stability have mainly concentrated on Al-Cu-Co and Al-Ni-Co (see (1,2) for review). Nevertheless, there are still many open questions concerning the constitution of these alloy systems and the transformation behavior of the D-phases. The ternary Al-Ni-Co phase diagram was recently studied in the vicinity of the D-phase (3,4). The 600, 700, 850 and 1000℃ isothermal sections of this phase diagram were determined in Ref.3 by means of powder x-ray diffractometry. The partial 650 and 850℃ sections are presented in (4) where the authors used powder x-ray diffractometry and transmission electron microscopy. Some information concerning the Al-Ni-Co D-phase(s) of different compositions was also presented in Refs.5-7.