Homogeneous titanium tungsten alloys produced by powder metal technology

Abstract

The present disclosure is related to homogeneous alloys comprising titanium and 9% to less than 20% by weight of tungsten, wherein the alloy has a yield strength of at least 120,000 psi and ductility of least 20% elongation; and with further alloying an ultimate tensile strength of at least 200,000 psi and useful ductility of at least 2% elongation; and with the addition of ceramic particulate reinforcements can exhibit an ultimate tensile strength of at least 180,000 psi. Products and metal matrix composites comprising such homogeneous alloys are also disclosed. The metal matrix composites further comprise a discontinuous reinforcement chosen from TiC, TiB₂, or TiB, particles or combinations of such particles. Method of making such alloys and composites as well as products made from such alloys and composites are also disclosed.

Description

[0001] This application claims the benefit of priority to provisional application 60 / 772,896, filed Feb. 14, 2006, which is herein incorporated by reference in its entirety.[0002] Disclosed herein are homogeneous titanium-tungsten alloys and metal matrix composites having highly desirable properties. Also disclosed are methods of making such alloys and composites, as well as products comprising such alloys and composites. [0003] Titanium metal has typically been alloyed with other metallic elements to increase the tensile strength over the pure metal. Early commercial titanium alloying elements Fe, Mn, and Cr improved strength but drastically lowered the ductility. Good ductility is desired in the typical component both to be formable (malleable) enough to produce the final shape by metalworking and to possess sufficient fracture resistance to deformation for use in the end-use application. [0004] With the development of the Ti-6Al-4V alloy (U.S. Pat. No. 2,906,654), which is herein...

AI Technical Summary

Benefits of technology

[0010] The present disclosure describes a method of making a heat treatable titanium base alloy that possesses combinations of properties that make them highly desirable. For example, in one embodiment of the invention there is described an alloy comprising titanium and 9 to less than 20% by weight of tungsten, wherein the alloy exhibits a yield strength of at least 120,000 psi and a ductility of at least 20% elongation. Applications for these highly ductile alloys include th...

Problems solved by technology

Early commercial titanium alloying elements Fe, Mn, and Cr improved strength but drastically lowered the ductility.

Although several later alloys were developed, such alloys achieved only incremental improvements in specific properties such as higher elevated strength, better weldability or improved fatigue strength.

For many metal working processes such as sheet bending, cold drawing and the manufacture of foil and thin wall tubing (e.g. aircraft hydraulic tubing), even Ti-6Al-4V becomes difficult to fabricate.

In this way the ductility is improved but at a significant sacrifice of strength.

However this heavy metal element caused severe segregation problems when incorporated in the ingot melting tec...