Rhenium is a rare refractory metal with high melting point, high strength, good plasticity and excellent mechanical stability. Its melting point is second only to tungsten, up to 3180 ℃. Rhenium has no brittle critical transition temperature. Rhenium has good creep resistance under high temperature, rapid cooling and rapid heating conditions. It is suitable for ultra-high temperature and strong thermal shock working environment.

Zirconium easily absorbs hydrogen and forms a variety of zirconium hydride mesophase. When the temperature is higher than 300 ℃, zirconium reacts with hydrogen. When the temperature reaches 400 ℃, the reaction speed is accelerated and solid solution is formed.