Abstract
The paper reflects on the usefulness of the alloy design methodology NICE (Niobium Intermetallic Composite Elaboration) for the development of new Nb-containing metallic ultra-high-temperature materials (UHTMs), namely refractory metal (Nb) intermetallic composites (RM(Nb)ICs), refractory high entropy alloys (RHEAs) and refractory complex concentrated alloys (RCCAs), in which the same phases can be present, specifically bcc solid solution(s), M5Si3 silicide(s) and Laves phases. The reasons why a new alloy design methodology was sought and the foundations on which NICE was built are discussed. It is shown that the alloying behavior of RM(Nb)ICs, RHEAs and RCCAs can be described by the same parameters. The practicality of parameter maps inspired by NICE for describing/understanding the alloying behavior and properties of alloys and their phases is demonstrated. It is described how NICE helps the alloy developer to understand better the alloys s/he develops and what s/he can do and predict (calculate) with NICE. The paper expands on RM(Nb)ICs, RHEAs and RCCAs with B, Ge or Sn, the addition of which and the presence of A15 compounds is recommended in RHEAs and RCCAs to achieve a balance of properties.
Highlights
The targets given to the aerospace industry by international regulatory authorities regarding the environmental impact of aircraft in the future could be met with changes in airframes and aeroengines
The above-mentioned interrelationships of alloys and their phases regarding (i) alloying behavior, (ii) properties and (iii) solute concentrations are captured in the alloy design methodology NICE, the development of which was based on data for refractory metal (RM)(Nb)ICs and was expanded to include data for RM(Nb)ICs that are HEAs, refractory high entropy alloys (RHEAs) and refractory complex concentrated alloys (RCCAs)
This paper considered metallic ultra-high-temperature materials (UHTMs) (excluding RM(Mo)ICs) that are under development as potential replacements of Ni-based superalloys for critical applications in aeroengines and must comply with specific property goals
Summary
The targets given to the aerospace industry by international regulatory authorities regarding the environmental impact (noise, emissions) of aircraft in the future could be met with changes in airframes and aeroengines. RM(Nb)ICs, RHEAs and RCCAs share the same alloying additions, and the parameters δ, ∆χ, VEC, ∆Hmix, ∆Smix and Ω (= Tm∆Smix/|∆Hmix|) (see Appendix A) describe their alloying behavior as they do for HEAs [1,3,8,13,23].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
