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HDH Processing Services
The Solar Atmospheres Research and Development Team successfully developed hydriding production cycles which provide a metal hydride from recyclable metal parts. A separate dehydriding process for the crushed metal hydride powder is also available to supply you with a lightly sintered pure metal powder. Solar currently performs hydriding and dehydriding cycles on a regular basis.
The Hydriding Step
The Hydride/Dehydride (HDH) process has been known for many years in the manufacturing of transition metal powders such as tantalum, niobium, vanadium, and titanium. These particular metals have a unique characterisitic: they undergo a reversible reaction (Equation 1) during hydriding. Vacuum purification and activation of the metal is necessary before hydrogen is readily absorbed to form the metal hydride. Absorbed hydrogen leads to an expanded metal lattice which promotes cracking and embrttlement. Once embrittled, the material is returned to you to be crushed for further processing.
Equation 1:
The reversible hydride/dehydride process, where M is the metal and MHx is the metal hydride. The metal hydride formation is exothermic; heat is released during the reaction. The dehydride step is endothermic; heat must be provided to the reaction…
Figure 2:
a. Hydrogen molecules adsorb onto the metal lattice
b. Absorption and chemisorption lead to an expanded metal lattice.
Dehydriding Step
The dehydriding step of the HDH process (Equation 1) process is run in vacuum to convert the powdered metal hydride to the pure metal powder. Heating in vacuum helps remove absorbed hydrogen quickly and efficiently without contamination from oxygen and nitrogen. Careful control of heating rates and final dehydriding temperature will result in a powder with minimum sintering.