Experimental Study of the Cr-Hf-Nb System: Liquidus Projection and 1200 °C Isothermal Section

João Carlos Jânio Gigolotti , Antonio Augusto Araújo Pinto da Silva , Gilberto Carvalho Coelho (1) , Carlos Angelo Nunes (1) , Jean-Marc Joubert (2)

1 USP - Universidade de São Paulo = University of São Paulo
2 ICMPE - Institut de Chimie et des Matériaux Paris-Est

Phase equilibria data from ternary Cr-Nb-X (X = Hf, Ta, Ti, Zr) systems are relevant to the development of Niobium-silicide based composites for use in jet engines. Such systems present at several temperatures a pseudo-binary of Cr2Nb-Cr2X Laves phases. This work presents the experimentally determined liquidus projection and the 1200 °C isothermal section for the Cr-Hf-Nb system based on microstructural characterization of as-cast and heat-treated alloys. The microstructural characterization using X-ray diffractometry, scanning electron microscopy and electron probe microanalysis showed four eutectic-type monovariant reactions and two class II invariant reactions in the liquidus projection. The

Mots clés: Intermetallics; Cr-Hf-Nb system; phase diagram; phase stability; microstructure

Domaines: Chimie; Matériaux

João Carlos Jânio Gigolotti, Antonio Augusto Araújo Pinto da Silva, Gilberto Carvalho Coelho, Carlos Angelo Nunes, Jean-Marc Joubert. Experimental Study of the Cr-Hf-Nb System: Liquidus Projection and 1200 °C Isothermal Section. Journal of Phase Equilibria and Diffusion, 2020, 41 (5), pp.702-721. ⟨10.1007/s11669-020-00838-w⟩. ⟨hal-03030400⟩