1. Field of the Invention
This invention relates to the field of thermal mechanical processes for the alpha/beta titanium alloys and the articles produced thereby.
2. Description of the Prior Art
The alpha/beta titanium alloys are well known in the art, and are described in the Metals Handbook, Vol. 1 (1961) at pp 1147-1156. These alloys, and various proceses applicable thereto are the subject of U.S. Pats. Nos. 2,801,167; 2,974,076; 3,007,824; 3,147,115; 3,405,016 and 3,645,803. In particular, U.S. Pat. No. 3,007,824 discloses a surface hardening process applicable to a specific alpha/beta alloy which involves heating the article at a temperature within the beta phase field and then quenching. No deformation is required. U.S. Pat. No. 3,405,016 discusses a heat treatment, for maximizing the formability of alpha/beta alloys, involving quenching from the beta phase field followed by deformation in the alpha/beta phase field.
The beta forging of the alpha/beta alloys is described in the Metals Handbook, Vol. 5 (1970) pp 143-144 wherein it is noted that beta forging as conventionally employed incorporates deformation both in the beta phase field and the alpha/beta phase field. The subject of beta forging is also discussed in Metals Engineering Quarterly, Vol. 8, Aug. 1968, at pp 10-15 and 15-18. These references imply that beta forging may have an adverse effect upon fatigue properties.