Microstructural observation of active nucleants in Al-Ti-B master alloys. (Reannouncement with new availability information)

Technical Report · Thu Dec 31 04:00:00 EST 1992

OSTI ID:189802

Suarez, O M; Perepezko, J H

The microstructural development and active nucleant site evaluation in Al-5Ti-lB and Al-5Ti-0.2B alloys have been investigated using the droplet emulsion technique DET and differential thermal analysis DTA. The droplet approach provides a unique experimental tool for the isolation and observation of the different potency levels of individual particles. Microstructural development in these alloys was examined following controlled quenching experiments; resultant metallographic examination allowed for the positive identification of the most effective nucleation substrates. The solidification pathway involves the formation of the Al3Ti phase with the subsequent nucleation of the Al phase on the Al3Ti substrate. Primary Al3Ti phase morphology in Al-Ti-B alloys does not appear to have a significant effect on the nucleation site potency. The solidification pathways observed suggest that B-rich compounds are not necessarily the primary nucleation substrates-for the Al phase.... Aluminum alloys, Grain refinement, Solidification, Nucleation, Thermal Analysis, Powders.

• Research Organization: Wisconsin Univ., Madison, WI (United States). Dept. of Materials Science and Engineering
• OSTI ID: 189802
• Report Number(s): AD-A--260424/7/XAB; CNN: Grant DAAL03-90-G-0042
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
BORON ALLOYS
DIFFERENTIAL THERMAL ANALYSIS
MICROSTRUCTURE
MORPHOLOGICAL CHANGES
QUENCHING
TITANIUM ALLOYS