You are on the right track. In the early smaller atomic b configurations, metallic beryllium was compressed (sintered) into a shield to reflect the released particles back into the reaction to re collide and produce a more efficient yield.


In the alloying of aluminum (mixing in a tiny amount) many things are used with sometimes startling results.

Nothing (worth mentioning) is made of just Beryllium.

The spring contact carrier arms of relays are made from copper alloyed with beryllium.