Critical Materials Atlas
Decision layer · substitution networks

Substituting a material only helps if it moves the chokepoint

“Just use something else” is the reflex answer to a supply dependency. But a substitute is only a real escape if it sits in a less concentrated supply chain. Some swaps genuinely exit — LFP drops cobalt for iron, ceramic capacitors replace tantalum. Others help only in some uses (silicon for gallium, sodium-ion for lithium), and some just move the grip to another single country — more nickel for less cobalt, niobium for tantalum. The atlas’s own concentration numbers say which is which.

How to read this. Each row is a real substitution, from a material to what can replace it in a named application. The percentages are the top producer’s share of each material’s mine supply (World Mining Data). The classification is the whole point: an escape lands in an abundant or diffuse material; a shift lands in another chokepoint. A finding that doesn’t change what you’d do isn’t finished — so this page ends every dependency with the honest verdict on whether substitution is a way out or a trap. Edges curated from USGS MCS substitutes + battery/magnet/semiconductor domain knowledge; not exhaustive. Reproducible: build_substitution.py → substitution.json.

Two honest limits. (1) The share is mine concentration; for materials whose real chokepoint is refining or separation — lithium, gallium, graphite, rare-earth magnets — the binding concentration is downstream and higher than the mine number here, so read those rows against the Chokepoint Map. (2) An “escape” means the substitute is geologically abundant (iron, ceramics, silicon, sodium); we do not measure the substitute’s own processing concentration, so it is an escape from this material’s exposure, not a guarantee the new chain is unconcentrated.

The decision that falls out

Substitution is a real lever — but only pointed the right way. The swaps worth public money and R&D are the ones that escape to abundance: they are the only moves that actually reduce the number of chokepoints in the system, rather than trading one country’s grip for another’s. LFP for cobalt, ceramic capacitors for tantalum — these shrink the map. Most substitutions only help in some uses (silicon for gallium, sodium-ion for lithium, no-magnet motors for some drivetrains): real relief, but partial — the material stays load-bearing everywhere else. The shifts — more nickel for less cobalt, niobium for tantalum, palladium for platinum — feel like progress and deliver none: the dependency simply changes address. Read alongside Break the chokepoint (who could build an alternative supplier) and the Chokepoint Map (why each stage concentrates): substitution is the one lever that can remove a chokepoint instead of relocating it — when it escapes.