I've read that iridium is used in the impact shielding of radioisotope thermoelectric generators (RTG) on spacecraft because of its hardness, high melting point, and extreme corrosion resistance. With stats like that, why isn't it being used in more applications? I know it is expensive, but so are many other exotic alloys and composites. It seems that it would be perfect for numerous aggressive environment applications but is largely ignored. Any thoughts on other uses/reasons for non-use?
Thanks!
Jim Painter Materials Science and Engineering Georgia Institue of Technology