Germination and selection of phases in refractory metals and alloys - Experimental approach with drop tube and theoretical approach with first-principles calculations

The refractory metals and alloys play an increasingly important role in man y areas to be applied in the most severe thermal and chemical environments. Solidification under weightless conditions realized in the 50-meters high Grenoble drop-tube is essential to study crystalline nucleation and phase s election phenomena and so to contribute to the development of high-temperat ure metallic materials. First-principles calculations of structural stabili ty are used to identify the intervening metastable phases and to provide gu idance in understanding the origin of metastable phenomena. An ESA Topical Team is now created on the Solidification of refractory metals and alloys.