US2810642A - Titanium-aluminum-silver alloys - Google Patents

Description

U t d ms. Parent 2,810,642 TITANIUM-ALUMINUM-SILYER ALLOYS Robert I. Jaltee, Worthington, and Horace R. Ogden, (Columbus, Ohio, asslgnors, bynaesne assignments, to Rem-Cru Titanium, ]nc., Midland, Pin, a corporation of Pennsylvania No Drawing. Application January 15, 1953, Serial No. 331,504

9 Claims. (Cl. 7 -1755) This invention pertains to ductile titanium-base alloys containing aluminum and silver as essential constituents. Broad and preferred ranges for the aluminum and 2,810,642 Patented Oct. 22, 1957 ice an ultimate strength at least ten percent in excess of that of the unalloyed titanium base metal, consistent with retention of good ductility. For the broad range oi analysis the minimum bend ductilities do not exceed T or possess tensile elongations under about 2%. For the preferred range of analysis the minimum bend ductilities do not exceed about 7 T, with elongation ranging up wards of about 10%.

Owing to their substantially all-alpha microstructure the alloys may be welded without appreciable impairment of ductility in the welded as compared to the non-welded portions.

The following Table 1 gives mechanical properties of typical alloys according to the invention, as produced from titanium base metal of commercial purity. In the table VHN designates Vickers hardness, while MBR signifies Minimum bend radius.

Table I MECHANICAL PROPERTIES OF Tl-Al-Ag ALLOYS [These alloys were 980 C. torgeg, 850 0. rolled to 0.040 inch, and annealed two hours at 8 0 C. and rapidly cooledJ silver contents consistent with retention of adequate ductility for fabrication purposes are as tollows:

Range. Percent Broad Preferred The alloys of the invention may be materially strengthened without undue loss of ductility by controlled additions of the interstitials carbon, oxygen and nitrogen in amounts ranging up to about 0.2% each, the aggregate content not to exceed about 0.6%.

These alloys may be made by melt-casting in a cold mold, employing an electric arc in an inert atmosphere, or may be produced in other ways in which the alloy is rendered molten before casting.

The titanium base metal employed may be the product of high purity obtained by the iodide" process debe the product of commercial purity produced by the scribed in U. S. Patent 1,671,213 to Van Arkel; or may magnesium reduction of titanium tetrachloride by the process described in U. S. Patent 2,205,854 to Kroll; or by other procedures producing titanium metal of equivalent purity.

The alloys of the invention possess a substantially allalpha microstructure at room temperature. This results from the alpha microstruclure of the titanium at room temperature, and the fact that aluminum together with the interstitials carbon, oxygen and nitrogen are all alpha promoters or stabilizers, while silver has so little efiect on the beta transus temperature of titanium that its effect is practically neutral. Although formerly considered an alpha stabilizer it now appears more properly grouped as a borderline beta stabilizer.

These alloys are further characterized in possessing The following Table 11 gives test data on the weldability of the alloys of Table I as are welded in an inert atmosphere, viz. argon.

Table II MBR, T

Composition, Percent (Balance Titanium) Welded Not Welded It will b seen from the above data that the ductility of these alloys is substantially unaffected by welding.

We claim:

1. A titanium base alloy consisting essentially of about: 0.5 to 8% aluminum, 0.5 to 15% silver, and up to 0.2% each of carbon, oxygen and nitrogen, characterized in having an ultimate strength at least ten percent in excess of the unalloyed titanium base metal, and a minimum bend radius of not over 20 T.

2. A titanium base alloy consisting essentially of about: 1 to 7.5% aluminum, 1 to 10% silver, and up to 0.2% each of carbon, oxygen and nitrogen, characterized in having an ultimate strength at least ten percent in excess of the unalloyed titanium base metal, and a minimum bend ductility of not over 7 T.

3. An alloy consisting essentially of about: 0.5 to 8% aluminum, 0.5 to 15% silver, up to 0.2% each of carbon, oxygen and nitrogen, balance titanium, characterized in having an ultimate strength at least ten percent in excess of the unalloyed titanium base metal, and a minimum bend radius of not over 20 T.

4. An alloy consisting essentially of about: 1 to 7.5%

aluminum, about 1 to 10% silver, up to 0.2% each of carbon, oxygen and nitrogen, balance titanium, characterized in having an ultimate strength at least ten percent in excess of the unalloyed titanium base metal, and a minimum bend ductility of not over 7 T.

5. An alloy consisting of about: 0.5 to 8% aluminum, 0.5 to 15% silver, up to 0.2% each of carbon, oxygen and nitrogen, balance titanium, characterized in having an ultimate strength at least ten percent in excess of the unalloyed titanium base metal, and a minimum bend radius of not over 20 T.

6. An alloy consisting of about: 1 to 7.5% aluminum, about 1 to 10% silver, up to 0.2% each of carbon, oxygen 4 and nitrogen, balance titanium, characterized in having an ultimate strength at least ten percent in excess of the unalloyed titanium base metal, and a minimum bend ductility of not over 7 T.

7. An alloy consisting of 1-4% aluminum, 2-8% silver, balance titanium.

8. An alloy consisting of l-6% aluminum, 28% silver, balance titanium.

9. An alloy consisting of about: 0.5 to 8% aluminum, 0.5 to 15% silver, up to 0.2% each of carbon, oxygen and nitrogen, and the balance titanium.

No references cited.

Claims (1)

1. A TITANIUM BASE ALLOY CONSISTING ESSENTIALLY OF ABOUT:0.5 TO 8% ALUMINUM, 0.5 TO 15% SILVER, AND UP TO 0.2% EACH OF CARBON, OXYGEN AND NITROGEN, CHARACTERIZED IN HAVING AN ULTIMATE STRENGTH AT LEAST TEN PERCENT IN EXCESS OF THE UNALLOYED TITANIUM BASE METAL, AND A MINIMUM BEND RADIUS OF NOT OVER 20 T.