By Jack Sun · Updated October 20, 2026
Quick definition: Titanium felt and nickel felt are porous materials made by sintering metal fibers. Both can provide transport passages, conductive paths and structural support. Their material and surface behavior differ, so compare the metal, fiber structure and delivered surface separately.
A titanium sheet of felt can look very similar to a nickel sheet: a thin porous structure that can be cut to a drawing. Why does one assembly use titanium and another nickel? Can the same shape be made from a different material?
The answer depends on where the part works, its function and its environment. A similar outline can establish a similar installation form; it does not establish functional interchangeability.
This article compares pure titanium fiber felt with pure nickel fiber felt. Nickel alloys, nickel-plated materials and other composites require their own evaluation.
What titanium and nickel felts have in common
Both start with metal fibers bonded at contact points by sintering, retaining spaces between the fibers. This construction can provide:
- Connected passages for liquids and gases.
- Paths for electrons through the metal network.
- Support for an adjacent component or an added functional layer.
- Sheets that can be cut or fabricated to the required outline.
These describe potential functions, not identical performance in every product. High porosity alone does not describe pore connectivity, surface shape or compression behavior. Uniform contact and easy gas removal are not automatic advantages belonging to one metal alone.
Where the materials differ
Corrosion resistance needs an identified environment
Titanium’s protective surface oxide contributes to its corrosion behavior, but does not protect against every medium. Hydrofluoric acid, certain acidic fluoride environments and some reducing-acid conditions require particular attention. [1]
Nickel-based materials feature in alkaline electrolysis research and component designs. That does not establish resistance to every alkaline condition or make temperature, electrode potential and operating changes irrelevant.
“Titanium for acid, nickel for alkali” is therefore too broad to act as a selection rule. Even an acid or alkali with the same name can behave differently as concentration, temperature and electrochemical conditions change. Transferring experience between unlike environments can produce an unsuitable substitution.
Bulk material, fiber network and contact interface
Electrical comparisons involve at least three levels.
| Level | What is being considered |
|---|---|
| Bulk metal | The material’s own electrical properties |
| Porous felt | Fiber connections and paths through the skeleton |
| Component interface | Contact with neighboring parts and the delivered surface |
Bulk-metal data explain one aspect of the difference, but cannot directly predict installed resistance. Interfaces can also change during service.
Original research on titanium-fiber PTLs shows that surface treatments affect contact and durability. [2] The fact that a metal conducts electricity is consequently not a complete account of component behavior.
For an observed resistance difference, identifying whether it arises within the material or at an interface provides a more useful starting point than immediately changing the metal.
Softness, recovery and strength
A soft feel does not establish better compression recovery. Ductile starting material does not prove that every bond in the finished felt will remain unaffected.
Fiber shape, layup, sintered bonds, thickness and support all influence mechanical behavior. Identify whether the comparison concerns bending, compression, tension or another load.
A supported felt can feel different from an unsupported one made from the same metal. Hand bending can illustrate handling behavior, but does not establish long-term assembly performance.
Why different electrolysis environments use different materials
Titanium-based materials in PEM water electrolysis
The PEM anode presents an oxidizing, acidic electrochemical environment. Titanium-based porous materials are used in PTL research and engineering for this position.
The US Department of Energy’s electrolyzer supply-chain report identifies the higher anode potential as a reason corrosion-resistant materials matter in PEM components. [3]
A titanium felt must also serve water delivery, oxygen removal, contact and support. Coating requirements depend on the interface and durability objectives.
We supply coated and uncoated titanium sintered felt. Neither the coating label nor pure-titanium composition alone establishes suitability for a particular electrolyzer. Our titanium PTL guide explains the component’s role.
Nickel-based materials in alkaline and AEM electrolysis
Liquid alkaline and anion-exchange membrane water electrolysis have different architectures. The former normally uses a liquid alkaline electrolyte; the latter uses a membrane conducting hydroxide ions, with the feed arrangement depending on the design. [4]
Nickel-based porous materials can provide transport, conductive support or substrates for catalyst layers in relevant designs. Their precise role depends on electrode side and the complete assembly.
One AEM study compared nickel foam, nickel felt and titanium felt, relating performance under its test conditions to pore structure. [5] Its conclusions support evaluating material and structure together, rather than declaring nickel felt superior in every electrolyzer.
Our nickel fiber felt page describes related supply forms.
Anode and cathode conditions are different
Even within the same cell, the two electrodes experience different reactions and potentials. Experience on one side does not automatically qualify a material on the other.
Naming the component position is more informative than saying only “for hydrogen production.” It also helps distinguish parts described loosely as electrodes, diffusion layers or transport layers.
Comparing actual felt products
Equal thickness does not establish equal structure
Equal nominal thickness can accompany different area mass, pore structure, surface peaks and support construction. If transport or contact differs, check whether thickness is the only matched characteristic.
Otherwise, a structural difference may be wrongly assigned entirely to titanium versus nickel.
Equal porosity does not establish equal pathways
Porosity gives void volume fraction, not every pore throat, connection or directional path.
A titanium PTL study adjusted pore structure to balance contact and gas removal. Although its samples were not fiber felts, the general lesson is useful: solid contact and fluid transport can require coordinated design rather than maximizing one number. [6]
Higher porosity describes a difference; it does not independently prove better overall behavior.
Coated and uncoated samples answer different questions
Comparing coated titanium felt with uncoated nickel felt includes differences in material, structure and surface treatment.
To investigate the metal itself, identify other variables as far as practical. To compare two actual components, testing their delivered conditions can be appropriate, but the result belongs to those components.
Both comparisons can be useful when the question is clear. Neither supports extending a single product result to an entire material family.
Use comparable measurement and assembly conditions
Clamping can affect porous-material thickness and contact. Compare resistance, permeability or other results with identified sample states and methods.
This is not a request for every customer to prepare a complex test plan. Drawing-based fabrication starts from the drawing and agreed requirements. Specific variables become relevant when investigating a particular difference.
Substitution and cost
Installation fit and functional fit
Replacing titanium felt with an equal-outline nickel felt can change surface behavior, contact, loading and long-term stability. Separate two questions:
Can it be installed? The outline, thickness and construction must fit.
Can it perform the original role? The material and surface must suit the position and required function.
Confirming only the first can postpone discovery of a problem until operation. For an existing drawing, the specified material and structure should be followed rather than changed because another part looks similar.
Compare costs for the actual component
Raw material, fiber preparation, felt construction, tolerances, surface treatment and quantity all affect cost. A service-life comparison also needs operating evidence.
Neither metal name alone establishes a universally cheaper component or lower lifetime cost.
Likewise, melting point is not a felt’s allowable operating temperature. Atmosphere, loading, surface and component function affect the actual limit; ranking melting points does not resolve the application question.
Frequently asked questions
Can nickel felt directly replace a PEM anode titanium felt?
Not on outline and thickness alone. The PEM anode has specific material and electrochemical requirements. A material change requires evaluation.
Can titanium felt be used in AEM systems?
It cannot be universally excluded. Titanium felt has appeared in AEM research comparisons. Suitability depends on structure, surface and cell conditions.
Does nickel felt inherently have higher porosity and permeability?
No. These are characteristics of the actual product construction, not universal consequences of the metal name.
Is nickel felt a complete catalytic electrode?
Not necessarily. It can be an electrode material or catalyst substrate, but supplied felt is not automatically an electrode with a specified activation or catalyst treatment.
Can both felts always be cleaned and reused?
No general promise applies. Consider contamination, substrate, coating, joints and recovery of function before choosing backwashing, ultrasound or another method.
How does fabrication start when a drawing is available?
Use the specified material, dimensions, structure and surface requirements. Discuss significant uncertainties directly instead of turning a knowledge article into a mandatory questionnaire.
Conclusion
Titanium and nickel felts share a porous-fiber form, but differ in material and surface behavior.
Start with compatibility between the environment and material, then examine the structure’s function and the surface contact in the assembly. This explains their different uses without treating one product’s advantage as a universal material ranking.
Technical references
- TIMET — Corrosion Resistance of Titanium.
- Degradation of PGM and PGM-free Coatings on PEMWE Porous Transport Layers.
- US DOE — Fuel Cells and Electrolyzers Supply Chain Report.
- US DOE — Hydrogen Production: Electrolysis.
- Park et al. — Effect of pore structures in nickel-based porous transport layers for high-performance and durable anion-exchange membrane water electrolysis.
- Lee et al. — Titanium porous-transport layers for PEM water electrolysis prepared by tape casting.
Research sample results are not product guarantees, and the cited powder-based PTL research is not presented as a fiber-felt test.
By Jack Sun. Jack Sun has long worked in metal wire mesh weaving and industrial filter-element manufacturing. Our company is based in Anping, Hengshui, Hebei, China.
