SOLID SOLUBILITY LIMITS OF Y AND Sc IN THE ELEMENTS W, Ta, Mo, Nb, AND Cr

摘要

Alloys and diffusion couples of yttrium and scandium with the refrac¬tory elements Mb and Ta of Group V and Cr, MD, and W of Group VI have been examined "by means of the optical microscope, X-ray diffraction, and mass spectrometry. The results indicate that the solid solubility of Y and Sc in these elements is less than 1 part per million. This is in conformity with the Hume-Rothery Rule that only a very restricted range of solid solu¬tion can be expected when the atomic diameter of solvent and solute differs by more than 14 to 15 per cent.