? – ?’ strengthened tungsten free cobalt-based superalloy

摘要

Embodiments herein present the invention of a class of Tungsten (W) free Cobalt based (? – ?’) superalloys with the basic chemical composition comprising in % by weight: 0.5 to 10Aluminium (Al) and 1 to 15Molybdenum (Mo) with atleast one or both of0.5 to 12Niobium (Nb) and 0.5 to 12Tantalum (Ta), with the remainder being Cobalt (Co). Some part of the cobalt can be replaced by nickel (50% or less). In Nickel added alloys, some part of either cobalt of nickel can be replaced by atleast one among the transition metal selected from the group consisting of 10% or less Iridium, 10% or less Platinum, 10% or less Palladium, 15% or less Chromium and combination thereof. Again in nickel added alloys, further addition of atleast one among the transition metals zirconium (5% or less), hafnium (5% or less), vanadium (5% or less), titanium (5% or less), and yttrium (5% or less), boron (2% or less), carbon (2% or less), rhenium (10% or less), ruthenium (5% or less) for further fine tune the solvus temperature, volume fraction of ?’ and creep properties.