The quenched and aged Ti-6A1-4V alloy used in the Atlas missile has yield points of 229 ksi at -320°F, 165 ksi at -70°F, and 120 ksi at 70°F. Suppose small cracks 0.02 in. long were discovered on...

The quenched and aged Ti-6A1-4V alloy used in the Atlas missile has yield points of 229 ksi at -320°F, 165 ksi at -70°F, and 120 ksi at 70°F. Suppose small cracks 0.02 in. long were discovered on cryogenic storage containers made from this alloy whose fracture toughness is 50 ksi-in.^^^. Estimate the ductile-to-brittle fracture transition temperature of this alloy. Would it be safe to expose these containers to liquid nitrogen temperatures (77 K)?