Patent ID: 11920218
Assignee: THE BOEING COMPANY
Field: Materials, metallurgy (Chemistry)
Classification: CPC C | IPC C

Claim 11:
12. A manufacturing method for the fastener stock in accordance with claim 1 which includes melting of titanium alloy ingot consisting of, in weight percentages: 5.5 to 6.5 Al, 3.0 to 4.5 V, 1.0 to 2.0 Mo, 0.9 to 1.5 Fe, 0.8 to 1.5 Cr, 0.05 to 0.5 Zr, 0.2 to 0.3 O, 0.05 max. N, 0.08 max. C, 0.25 max. Si, and balance titanium and inevitable impurities, characterized by the value of aluminum structural equivalent [Al] eq in the range of 8.2 to 9.5, and the value of molybdenum structural equivalent [Mo] eq in the range of 6.0 to 8.5, where the equivalents are defined by the following equations:

[Al] eq=[Al]+[O]×10+[Zr]/6;

[Mo] eq=[Mo]+[V]/1.5+[Cr]×1.25+[Fe]×2.5,, conversion of the ingot to forged billet at beta and/or alpha-beta phase field temperatures, machining of forged billets, hot rolling at a heating temperature of beta and/or alpha-beta phase field to produce a rolled stock with diameter of 6.5 mm to 12 mm (0.256 inches to inches), subsequent annealing of a rolled stock at a temperature of 550° C. to 705° C. (1022° F. to 1300° F.) for at least 0.5 hour followed by drawing to produce the drawn round wire with diameter up to 10 mm (0.394 inches) and subsequent annealing at a temperature of 550° C. to 705° C. (1022° F. to 1300° F.) for at least 0.5 hour.