Nickel-containing alloys, method of manufacture thereof and articles derived thereform

Abstract

Disclosed herein too is a method for manufacturing an article comprising casting an alloy comprising about 1.5 to about 4.5 weight percent aluminum; about 1.5 to about 4.5 weight percent titanium; up to about 3 weight percent niobium; about 14 to about 28 weight percent chromium; about 10 to 23 weight percent cobalt; about 1 to about 3 weight percent of tungsten, rhenium, ruthenium, molybdenum, or a combination thereof; about 0.02 to about 0.15 weight percent of carbon; about 0.001 to about 0.025 weight percent of boron; up to 0.2 weight percent of zirconium, hafnium, or a combination thereof; into a mold.

Description

technical field [0001] The present disclosure relates to nickel-containing alloys, methods of making them, and articles derived therefrom. Background technique [0002] Superalloys suitable for turbine nozzle and airfoil applications typically exhibit high temperature strength, corrosion resistance, and properties such as castability and weldability. Unfortunately, methods that optimize one kind of performance often result in reduced performance of another. The approach to alloy design often results in compromises to obtain the best overall mix of properties that meet the various requirements of the part design. In this design approach, it is rare to optimize any one performance. Instead, the best compromise between desired properties is obtained by developing a balanced chemical composition and proper heat treatment. [0003] Cobalt-containing alloys have been found for use in first-stage turbine nozzle applications, although they are susceptible to thermal fatigue fract...

AI Technical Summary

Problems solved by technology

However, in post-stage nozzles, it was found that cobalt-based alloys were creep-limited to the point where downstream creep of the nozzle would result in an unacceptable reduction in turbine diaphragm clearance

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