refractory metal

Miracle is concentrating on a cluster of elements in the centre of the periodic table known as the refractory metals. These elements, including molybdenum and niobium, have unusually high melting points around 2500°C, compared with 1455°C for nickel, on which jet engine alloys are now based. […] So far he has shown that high-entropy refractory metal alloys do indeed remain strong at temperatures beyond the wilting point of existing nickel superalloys.