Multi-component, heatproof alloys with niobium


I. M. Frantsevich Institute for Problems of Materials Science of the NAS of Ukraine, Krzhizhanovsky str., 3, Kyiv, 03142, Ukraine
Electron Microscopy and Strength of Materials - Kiev: Frantsevich Institute for Problems of Materials Science NASU, 2016, #22


In this paper the grain structure, phase composition and mechanical properties of multicomponent, heatproof alloys with composition of Nb—16Cr—16Al—16Ti— 16Me—4Si% (at.), where Me is Mo or Zr is investigated. It is shown that the alloy Nb— 16Cr—16Ti—16Mo—16Al—4Si is formed of over 90% (vol.) BCC Nb-based solid solution. Chromium and silicon that have a much smaller atomic radii than more closer to each other in size atomic radii of the remaining alloy components form their phases which summary reaches up to 10% (vol.). Insertion Zr instead of Mo leads to a significant change in the ratio of composition and amounts of the phases formed in the alloy, as well as its mechanical properties. The increase in non-compliance with the atomic radii of the components after insertion of zirconium complicates the formation of a single-phase alloy BCC. Besides the high entropy of mixing the formation of phases in a multi-component alloy is greatly influenced by the ratio of the atomic radii of the alloy components. Full text download