Aerospace suppliers test rare-earth alternatives to ease reliance on China

European thermal coatings producer Oerlikon Metco OERL.S said it already sells some rare-earth-free products and has more in development, including zirconia-based thermal barrier coatings made with magnesium and calcium oxides that predate today's rare-earth-enhanced materials.

Some U.S. thermal-coating suppliers are also exploring non-rare-earth alternatives for less critical components, one industry source said.

Recycling surplus coating materials could also help ease supply constraints, a separate industry source said.

Still, such efforts can only alleviate, not solve, aerospace's reliance on China.

"Even under optimistic scenarios, we are years, not months, away from breaking our dependency on China for rare earths," said Geoffrey Gertz, a former official on the White House National Security Council and senior fellow at the Center for a New American Security.