Definition of "rhenium" [rhenium]

• A rare, dense, silvery-white metallic element with a very high melting point used for electrical contacts and with tungsten for high-temperature thermocouples. Atomic number 75; atomic weight 186.2; melting point 3,180°C; boiling point 5,627°C; specific gravity 21.02; valence 1, 2, 3, 4, 5, 6, 7. See Table at element. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Sometimes platinum is combined with a second catalyst (bimetallic catalyst) such as rhenium or another noble metal."
• "High levels of refractory elements such as rhenium can make the alloys prone to the formation of what are known as deleterious topologically close packed"
• "By tweaking the mix of other hardening additives like nickel and molybdenum, which are cheaper and more abundant, GE was able to cut the rhenium content in its jet-engine blades to 3% from 6%."