Solution heat treatment and overage heat treatment for titanium components

摘要

A method of fabricating a Ti-6Al-4V titanium alloy component including solution heat treating a forged Ti-6Al-4V titanium alloy component at a temperature within the alpha+beta two-phase field for the material of the component for a predetermined period of time, and subsequently cooling the component. The component is then age heat treated using an overaging process at a predetermined overaging temperature for a predetermined time, and the component is cooled to room temperature. The overaging temperature is selected to be a higher temperature than an aging heat treatment temperature for effecting a maximum yield strength in the component.

主权项

1. A method of fabricating a Ti-6AI-4V titanium alloy component comprising sequential steps of:
a) providing a forged Ti-6AI-4V titanium alloy component; b) solution heat treating the component at a solution temperature relatively high within an alpha +beta two-phase field for the material of the component and at least 54° F. below the beta transus temperature comprising a temperature within a range of about 1675° F. to about 1775° F., and for a predetermined period of time; c) cooling the component to a temperature below the temperature of the alpha +beta two-phase field; d) overage heat treating the component comprising an overaging process at a predetermined overaging temperature comprising a temperature greater than 1357° F. and less than 1500° F. for a predetermined time; e) cooling the component from the predetermined temperature of step d) to room temperature; and wherein the overaging temperature comprises a temperature lower than the solution temperature but higher than an aging heat treatment temperature for effecting a maximum yield strength in the component, and wherein the resulting structure of the component has a fracture toughness, KIC, greater than 50 ksi-in1/2and a yield strength greater than about 125 ksi.