Gamma - gamma prime strengthened tungsten free cobalt-based superalloy

Abstract

Embodiments herein present the invention of a class of Tungsten (W) free Cobalt based (γ-γ′) superalloys with the basic chemical composition comprising in % by weight: 0.5 to 10 Aluminium (Al) and 1 to 15 Molybdenum (Mo) with at least one or both of 0.5 to 12 Niobium (Nb) and 0.5 to 12 Tantalum (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 at least 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 at least 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 γ′ and creep properties.

Description

TECHNICAL FIELD[0001]The present disclosure generally relates to the field of materials science, and more specifically to a cobalt-base superalloy with a γ / γ′ microstructure. Embodiments herein particularly relate to a composition of high temperature resistant, tungsten free cobalt based superalloy.BACKGROUND[0002]The background description includes information that may be useful in understanding the embodiments herein. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed embodiments, or that any publication specifically or implicitly referenced is prior art.[0003]For a vast majority of materials, the yield strength decreases with increasing temperature. As is obvious, a decrease in yield strength at high temperature becomes a limiting factor for use of such materials for high temperature applications. However, certain alloys such as superalloys (nickel, iron and cobalt based) exhibit superior mechanical properties even...

AI Technical Summary

Benefits of technology

[0015]Yet another object of the present disclosure is to provide a γ-γ′ cobalt based superalloys having better specific strength, com

Problems solved by technology

As is obvious, a decrease in yield strength at high temperature becomes a limiting factor for use of such materials for high temperature applications.

However, these alloys have high density, low creep strength, and ductility.

However, limiting factor for achieving this objecti

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