Low-density, W-free Co–Nb–V–Al-based superalloys with γ/γ’ microstructure

Enhancement of γ/γ’ Microstructured Cobalt Superalloys Produced from Atomized Powder by Creating a Harmonic Structure

“…For example, a number of recent studies describe substituting W or Al to improve the stability of the γ' area and even lower the alloy's density. Mo, Nb, or V have taken the role of W [23][24][25][26], and Ti and Ta have replaced Al [27,28]. The basal Co-9-9 alloy's high-temperature oxidation behavior can also be enhanced by small additions of Si and Cr [29].…”

Isothermal oxidation behavior of W‐free Co–Ni–Al‐based superalloy at high temperature

“…However, the W content in Co–Al–W ternary superalloys exhibits to be more than 9 wt%, which significantly enhances the density of the materials, and thus limits the application of this superalloy which the strength‐to‐weight ratio of which is critical. Until 2015, Makineni et al [ 4,5 ] developed new W‐free Co‐based superalloys with additions of Mo and Nb, and then other W‐free γ′‐strengthened Co‐based superalloys have been developed by researchers, such as Co–Nb–V, [ 6 ] Co–V–Ta, [ 7 ] Co–Al–Ta, [ 8 ] Co–Ti–Cr, [ 9 ] Co–Ni–Cr. [ 10 ] Therefore, the development of W‐free Co‐based superalloys by replacing W with Nb, V, Ta, and other alloying elements with the aim of reducing the density of superalloys is expected to achieve excellent high‐temperature performance.…”