Tough, high-strength titanium alloys; methods of heat treating titanium alloys
AssigneeThe Boeing Company
InventorRobert D. Briggs
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Abstract
The present disclosure describes methods of heat treating Ti-based alloys and various improvements that can be realized using such heat treatments. In one exemplary implementation, the invention provides a method of forming a metal member that involves forming an alloy into a utile shape and cooling the alloy from a first temperature above a beta transus temperature of the alloy to a second temperature below the beta transus temperature at a cooling rate of no more than about 30° F./minute. If so desired, the alloy my be treated for a period of about 1-12 hours at about 700-1100° F. Titanium alloys treated according to aspects of the invention may have higher tensile strengths and higher fracture toughness than conventional wrought, mill-annealed Ti 64 alloy.
Claims16
A method of forming a metal member, comprising:
- forming an alloy into a utile shape, the alloy consisting essentially of about 5 wt. % aluminum, about 5 wt. % molybdenum, about 5 wt. % vanadium, and about 3 wt. % chromium with the balance consisting of titanium;
- and
- cooling the alloy with the utile shape from a first temperature above a beta transus temperature of the alloy to a second temperature below the beta transus temperature at a cooling rate of no more than about 5° F./minute, wherein the second temperature is less than 700° F.
A metal component, comprising:
- a titanium alloy in a utile shape, the titanium alloy consisting essentially of about 5 wt. % aluminum, about 5 wt. % molybdenum, about 5 wt. % vanadium, and about 3 wt. % chromium with the balance consisting of titanium;
- and
- wherein a microstructure of the metal component comprises a beta phase and an acicular alpha phase in a basketweave pattern, and wherein the microstructure is generally free of grain boundary alpha phase as shown in FIG. 4.
A metal component, comprising:
- a titanium alloy in a utile shape, the titanium alloy comprising at least about 50 wt. % titanium and at least about 5 wt. % molybdenum;
- and
- wherein a microstructure of the metal component comprises a beta phase and an acicular alpha phase having a basketweave structure, and wherein the microstructure is generally free of grain boundary alpha phase as shown in FIG. 4.
Dependencies are inferred from the claim text.