Hydrogen Decrepitation Furnace

Selection criteria

Hydrogen pressure, dehydrogenation temperature, batch size.

Supply chain

Hydrogen-decrepitation furnaces are supplied by the same vacuum-furnace makers, largely Chinese for domestic magnet plants. Safety (hydrogen handling) and oxygen control are the main considerations.

Buyer FAQ

What are typical HD process conditions?

Flakes absorb hydrogen near room temperature at slightly above atmospheric pressure; the Nd-rich grain-boundary phase and the main phase expand and crack the material into coarse powder. Dehydrogenation then heats the batch under vacuum, typically around 500–600 °C, to drive off most of the hydrogen. Residual hydrogen and oxygen pickup should both be measured per batch.

What safety features should an HD furnace have?

Require hydrogen leak detection, explosion-proof electrics in the hydrogen zone, automatic nitrogen or argon purging before and after hydrogen admission, pressure relief and interlocked vacuum-integrity checks. The hydrided powder is pyrophoric, so unloading and transfer must stay under inert gas. Check that the hydrogen supply system meets local pressure-equipment and hazardous-area rules.

Batch rotary or continuous HD furnace?

Batch rotary furnaces are simpler and flexible for many alloy grades, typically holding several hundred kilograms to around one tonne per charge. Continuous lines give higher throughput and more consistent hydrogen and oxygen content but suit long runs of few grades. For supplier audits, the key question is how oxygen pickup is controlled between HD and jet milling.

Where it is used