Experimental investigation of kinetic parameters in the BCC region of the Al-Nb-V system

Abstract

Since the beginning of the 21st century, a new concept of alloys has attracted the interest of the scientific community. These are alloys with multi-principal elements, which are also known as high-entropy alloys. Considering the necessity of new materials for advanced high-temperature applications, refractory metals have been used as constituents of such alloys. Later, aluminum was added to these alloys with the objective of reducing their specific mass, a critical material selection criteria in the aerospace industry, leading to the low-density, refractory, multi-principal element alloys. In this context, one of the systems of interest is the ternary Al-Nb-V, more particularly the BCC phase stability region, for which there is no kinetic information involving the three elements. The aim of this work is to determine the fluxes and interdiffusion coefficients in the V-rich BCC region of the Al-Nb-V system at 1000°C and 1100°C. The alloys of the terminal phases of the diffusion couples will be arc-melted, cut into coupons and placed against each other by a mechanical system to maintain good contact at the interfaces. After heat treatements, the diffusion couples will be microstructurally characterized by scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS) and/or wavelength-dispersive spectroscopy (WDS). The diffusion parameters will be calculated according to the Whittle-Green method.