I. Gheorghe, Alu Menziken Aerospace / UAC, Canton, GA

Summary:

Present aluminum aircraft structures are facing a serious threat as the fiber reinforced polymer matrix composites are more seriously considered for structural aircraft components. In the same time new aircraft design criteria along with the ongoing need to reduce manufacturing and maintenance costs without sacrificing structural properties are imposing the development of new aluminum alloys to exhibit high strength and damage tolerance.

This paper will present some of the challenges that the new aluminum alloys are facing, many of these challenges being caused by a very tough carbon-fiber composite competition. Both systems have unique features not exhibited by the competitor system. Due to the very different nature of the two systems is many times difficult to make a head-to-head comparison. When making such assessment mechanical and corrosion properties, specific weight, acquisition and maintenance cost have to be taken in consideration. Aluminum alloy systems have the advantage of being a well established technology, therefore the integration of any new alloy system into a new aircraft design is considerable less expensive when compared to the composite alternative. The properties of a newly developed aluminum alloy with very high specific strength, good damage tolerance and corrosion resistance will be presented.

The mechanical and corrosion properties of 7136 T76511 as well as some of its current applications will be presented.