Extremely high Frequency
EHF GHZ
Millimeter Wave Microwave
Terahertz gap

Cobalt

https://banned.video/watch?id=5e8639d5d753df001e1eb96d
https://en.m.wikipedia.org/wiki/Hardnesses_of_the_elements_(data_page)

Hardnesses of the elements
Brinell Hardness (MPa)

cobalt 470–3000
titanium 716–2770

https://sciencing.com/what-are-the-uses-of-cobalt-12187711.html

https://www.cobaltinstitute.org/cobalt-uses.html

https://www.cobaltinstitute.org/superalloys.html

Superalloys are defined as "alloys developed for elevated temperature service where severe mechanical stressing is encountered and high surface stability is frequently required". There are three classes of alloys that meet this definition - cobalt-base, nickel-base and iron-base.

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http://archive.is/uv4GY

http://archive.is/9cnDe