A Study of the Effects of Hf and Sn on the Microstructure, Hardness and Oxidation of Nb-18Si Silicide-Based Alloys-RM(Nb)ICs with Ti Addition and Comparison with Refractory Complex Concentrated Alloys (RCCAs).

ABSTRACT: In this paper, we present a systematic study of the as-cast and heat-treated microstructures of three refractory metal intermetallic composites based on Nb (i.e., RM(Nb)ICs), namely the alloys EZ2, EZ5, and EZ6, and one RM(Nb)IC/RCCA (refractory complex concentrated alloy), namely the alloy EZ8. We also examine the hardness and phases of these alloys. The nominal compositions (at.%) of the alloys were Nb-24Ti-18Si-5Hf-5Sn (EZ2), Nb-24Ti-18Si-5Al-5Hf-5Sn (EZ5), Nb-24Ti-18Si-5Cr-5Hf-5Sn (EZ6), and Nb-24Ti-18Si-5Al-5Cr-5Hf-5Sn (EZ8). All four alloys had density less than 7.3 g/cm³. The Nb_ss was stable in EZ2 and EZ6 and the C14-NbCr₂ Laves phase in EZ6 and EZ8. In all four alloys, the A15-Nb₃X (X = Al,Si,Sn) and the tetragonal and hexagonal Nb₅

SUBMITTER: Zacharis E 

PROVIDER: S-EPMC9267193 | biostudies-literature | 2022 Jun

REPOSITORIES: biostudies-literature