Novel high entropy intermetallic compounds: Synthesis and detonation spraying

(NiCoFeCuMn)Zn ₃ and (NbTaVNiTiFe)Al ₃ high entropy intermetallic compound (HEIC) powders are fabricated by induction melting followed by ball milling. The fabricated (NiCoFeCuMn)Zn ₃ HEIC powder possesses a single γ-brass D8 ₂-type structure, while (NbTaVNiTiFe)Al ₃ exhibits D0 ₂₂ HEIC phase along with Ni ₄Ti ₃ and FeNi intermetallic inclusions. The microstructure of (NiCoFeCuMn)Zn ₃ HEIC powder consists of a homogenous distribution of constituent elements. In the microstructure of (NbTaVNiTiFe)Al ₃ , (TaNb)-rich and (FeNi)-rich regions are formed. A modified electronegativity parameter is proposed as a new indicator to design single high-entropy phases in ordered (A1A2A3 … An)B _m systems. The application of the prepared HEICs as precursor powders for detonation spraying (DS) is further examined. The results indicate that both powders can exhibit sufficient thermal stability during DS. The coatings exhibit sound bonding with substrate, and consist of lamellar microstructure with low porosities. It is predicted that HEICs, as a promising class of high entropy materials, are interesting candidates for a wide range of applications from coatings to catalysts.