Cedrick Meriman, SecondLife asked:
Do rare earth metals get used in alloys? Given their high price, I’d assume not.
Nick - Rare earth elements are just a certain part of the periodic table. It’s just a group of elements and some of them, such as Yttrium and Lanthanum, do find some small percentage uses in some modern alloys but as you say, there's no large scale use of them, just due to their high cost.
Ben - Roger, when you're designing new alloys or when you're modelling them, do you work around the cost? Are there ways that you can replace things that rare earth elements would otherwise do?
Roger - Yes, it’s certainly true that we consider the cost because certain elements, like rhenium for example in turbine blade alloys, are now very expensive, several thousand pounds per kilogram. When one is interested in building a jet engine with perhaps 100 blades per row then the cost can become significant quite quickly. So certainly, there are calculations done to trade off the relative benefits of elements like rhenium and tungsten, and molybdenum and other refractory metals against their disadvantages which are then costs and also their scarcity.
Gold has been used in alloys for eons.
OK, so in a thread about the rare earth metals reference is made to about 16 elements of which just 3 are actually rare earth metals.