TITANIUM AND THE U.S. NAVY

FROM:  DEPARTMENT OF DEFENSE ARMED WITH SCIENCE
Written on APRIL 12, 2012 AT 7:14 AM by JTOZER
The Strength of Titanium For The Navy
From the Office of Naval Research

Steel may have met its match.
An Office of Naval Research (ONR)-funded project will produce a full-size ship hull section made entirely with marine grade titanium using a welding innovation that could help bring titanium into future Navy ship construction.

The contractor team building this section recently completed the industry’s longest friction-stir titanium alloy welds and aims to complete the ship hull section this summer. Friction stir welds more than 17 feet long joined the titanium alloy plates for the section’s deck.

“This fast, effective friction stir weld technique is now an affordable manufacturing process that takes advantage of titanium’s properties,” said Kelly Cooper, the program officer managing the project for ONR’s Sea Warfare and Weapons Department.
What it means for the Navy

Titanium metal and its alloys are desirable materials for ship hulls and other structures because of their high strength, light weight and corrosion-resistance. If constructed in titanium, Navy ships would have lighter weight for the same size—allowing for a bigger payload—and virtually no corrosion. But because titanium costs up to nine times more than steel and is technically difficult and expensive to manufacture into marine vessel hulls, it has been avoided by the shipbuilding industry.
But perhaps not for much longer.

Researchers at the University of New Orleans School of Naval Architecture and Textron Marine and Land Systems are demonstrating the feasibility of manufacturing titanium ship hull structures. Using lower cost marine grades of titanium, they fabricated a 20-foot-long main deck panel—composed of six titanium plates, joined together by friction stir welding—as part of technology studies for an experimental naval vessel called Transformable Craft, or T-Craft.