Al-Li

From Wikipedia, the free encyclopedia

Al-Li alloys are a series of alloys of aluminium and lithium, often also including copper and zirconium. Since lithium is the lightest elemental metal, these alloys are significantly lighter than aluminium. Every 1% by weight of lithium added to aluminium reduces the density of the resulting alloy by 3%.^[1]

Al-Li alloys are primarily of interest to the aerospace industry, due to their weight advantage. They are currently used in a few commercial jetliner airframes, and the AgustaWestland EH101 helicopter.^[2]

The third and, as of 2006, current version of the U.S. Space Shuttle's external tank is principally made of Al-Li.^[3] In addition, Al-Li alloys are also used on both the Atlas V and Delta IV EELV rockets, and will be used by NASA for Project Constellation, primarily on its Ares I and Ares V rockets, as well as the Orion spacecraft.

Al-Li alloy swarf, scrap and other recycled material must be kept separate from other aluminium streams during recycling, as mixing Al-Li alloy with conventional aluminium recovery streams will cause extreme fire and explosion hazards.^{[citation needed]}