Abstract
NbSi2 layer with ca. 70 micormeter thickness was formed at the surface of a Nb plate by heating at 1200 K for 12 h in a Na-Si melt. The thickness of the NbSi2 layer increased with increasing heating-temperature and was proportional to the square root of heating-time. The shape and weight of the Nb plate with NbSi2 surface layer were almost maintained after heating at 1400 K for 10 h in air. However the plate was disintegrated into powders by heating at 1000 K for 10 h in air due to heavy oxidation known as the pest phenomenon.
