Patent ID: 7303638

Claim:
A method for cold forming a Ti 6-2-4-2 sheet, comprising: providing a Ti 6-2-4-2 sheet having a nominal thickness of less than about 0.1875 inches that has been duplex annealed according to AMS 4919 by heating the Ti 6-2-4-2 sheet to about 1650 ±25° F., holding the Ti 6-2-4-2 sheet at about 1650±25° F. for about 30±3 minutes, and cooling the Ti 6-2-4-2 sheet to room temperature in air, reheating the Ti 6-2-4-2 sheet to about 1450±25° F., holding the Ti 6-2-4-2 sheet at about 1450±25° F. for about 15±2 minutes, and cooling the Ti 6-2-4-2 sheet to room temperature in air; subjecting the Ti 6-2-4-2 sheet to a pre-forming annealing cycle comprising: heating the Ti 6-2-4-2 sheet to a pre-forming annealing temperature of about 1550-1750° F.; holding the Ti 6-2-4-2 sheet at the pre-forming annealing temperature for about 30 minutes; and cooling the Ti 6-2-4-2 sheet to room temperature at a first predetermined cooling rate; cold-forming the Ti 6-2-4-2 sheet into a cold-formed shape; and subjecting the cold-formed shape to a post-forming annealing cycle comprising: heating the cold-formed shape to about 1450±25° F.; holding the cold-formed shape at about 1450±25° F. for about 15±2 minutes; and cooling the cold-formed shape to room temperature at a second predetermined cooling rate.