5AL-2.5SN

Principal Design Features

This non-heat treatable, alpha alloy combines good weldability with stability and excellent strength from cryogenic through elevated temperatures. It is available at the mill level in sheet, strip, plate, bar, billet, extrusions and wire. Beta Transus (F +/- 25) 1900.

Applications

Primarily employed in aircraft engine and airframe applications.

Machinability

As a family, titanium and its alloys have developed a mystique as a nightmare to machine. This is simply not the case. Experienced operators have compared its characteristics to those found in 316 stainless steel. Recommended practice includes high coolant flow(to offset the material’s low thermal conductivity), slow speeds and relatively high feed rates. Tooling should be tungsten carbide designations C1-C4 or cobalt type high speed tools.

Forming

May be hot or cold formed using hydropress, power brake, stretch or drop hammer methods. Similar in characteristics to 300 series stainless steels.

Welding

Rated as “good” in terms of weldability.

Heat Treatment

This alloy is not hardenable by heat treatment.

Forging

Rough work at 1010-1038 C(1850-1900 F) and finish at 954-1010 C(1750-1850 F).

Hot Working

Hot forming will reduce both the springback and required forming forces, and will increase the overall ductility of the material.

Cold Working

The cold work characteristics of this material is similar to that of a moderately tempered austenitic stainless steel. In multiple cold forming operations, intermediate stress relief is recommended to prevent tearing or other material damage. Post-work an

Annealing

For full anneal, heat to 718-843 C(1325-1550 F) 4 hours, air cool. For intermediate stress relieving, heat to 538-650 C(1000-1200 F) for 1 hour, air cool.