Stronger than the Shuttle

Japan-based Kobe Steel claims that it has created the world’s strongest aluminium alloy – with a tensile strength of 780 MPa – using a spray forming process that it has developed.

Kobe Steel is now seeking to find applications for the new light weight, high strength alloy by making sample bars 10 mm in diameter and 100 mm in length available to engineers. It is also working to mass-produce bars, wire rods, shapes and plates made of the material.

“This value-added aluminium is suitable in applications where high performance is required,” said Senior Researcher Hideo Hata at Kobe Steel’s Materials Research Laboratory. “By 2008, we’re aiming to commercialise the new material for use in special purpose vehicles – such as race cars – and aircraft and aerospace parts,” he said.

The new aluminum alloy, under patent application, has a tensile strength of 780MPa, 10% higher than the 710 MPa of Weldalite, an aluminium-lithium alloy developed by Lockheed Martin Corporation that’s used in the External Fuel Tank of the Space Shuttle.

The ductility of Kobe Steel’s new alloy is also high. Generally speaking, as strength increases, material workability goes down. However, with a breaking elongation of 14%, Kobe Steel’s new material has nearly three times the ductility of Weldalite’s 5%. Ductility is 1.4 times that of titanium alloy and maraging steel. In addition, the new alloy has one of the highest specific strengths (the tensile strength divided by the density of the new material). The higher the specific strength, the lighter and stronger the material is.