Inventors:
Rabindra Mahapatra - Port Tobacco MD
Eui W. Lee - Maple Glen PA
Jeffrey Waldman - Huntington Valley PA
John H. Perepezko - Madison WI
Assignee:
The United States of America as represented by the Secretary of the Navy - Washington DC
International Classification:
C22C 1400
US Classification:
148562, 148404, 148421, 420418, 117 41
Abstract:
A process of preparing aligned, in-situ, two-phase single crystal alloys of titanium, aluminum and niobium which comprises growing the alloys at rates of about 3. 0 mm. to about 6. 0 mm. per hour by rotating a seed rod alloy consisting essentially of Ti-43 to 45 Al-10 to 12 Nb+0. 5 Si, in atomic percent, at about 7. 75 to 8. 25 RPM while in contact with a rotating feed rod alloy consisting essentially of Ti-43 to 45 Al-10 to 12 Nb, in atomic-percent, rotating at about 5. 75 to 6. 25 RPM in an atmosphere of substantially pure argon at melt temperatures ranging from about 1650Â C. to 1750Â C. to obtain two-phase single crystal alloys of Ti-43 to 45Al-10 to 12 Nb characterized as having improved ductility, excellent oxidation resistance, and high-temperature creep strength. These alloys are particularly useful for manufacturing high-temperature material components for internal combustion engines, gas turbines, and advanced aircraft engines.
