If you stick a steel poker into a blast furnace, it will quickly soften and sag. Even the toughest metals used in jet engines only work up to 1300 °C. A new niobium-based alloy holds its shape at 1500 °C, which is hotter than volcanic lava.
The secret lies in its internal structure. As the melt solidifies, it separates into two types of layers: hard plates of niobium carbide and soft interlayers of a niobium-molybdenum mixture. The result is like plywood, where layers of wood alternate with glue. The hard plates prevent the metal from flowing, while the soft interlayers allow it to bend rather than break.
The researchers tested it: after 100 hours in a furnace at 1400 °C, the layers neither thickened nor fused together. This means a part made from this alloy will last a long time. And crucially, the raw material costs about $85 per kilogram, similar to stainless steel, and parts can be made using conventional casting.
The melting point of NMC-1 is 2311 °C, just 166 °C below that of pure niobium. Moreover, the raw materials cost only about $85 per kilogram, comparable to some stainless steels.
In Arthur C. Clarke's novel 'The Fountains of Paradise', a space elevator requires a material with fantastic strength at high temperatures. Although NMC-1 is far from such requirements, the very idea of eutectic strengthening resonates with the quest for materials that can withstand extreme conditions.