Influence of the processing on the ordering process in the Al-Ti binary system with composition close to Al3Ti

Abstract

The phases and their stability in Al70Ti30, Al 75Ti25 and Al80 Ti20 planar flow cast ribbons and their master alloys have been studied. Analyses are based on the XRD and DTA measurements. In all samples the high-temperature Al 11Ti5 and Al5Ti2 superstructures (1d-APSs) have been present. The stable low-temperature phases Al2Ti, Al3Ti and Al have been identified, too. The 1d-APSs being formed as first during the quenching persist for considerable time also at low temperatures. During heating in reverse, only the 1d-APSs remain before melting, being formed after large superheating from all low-temperature phases in Al70Ti30 and Al75Ti25 alloys. The phase Al11Ti5 is reported in the Al3Ti and more Al-rich alloys for the first time. © 2009 IOP Publishing Ltd.