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

Abstract

A nickel-containing alloy is disclosed. The alloy contains about 1.5 to about 4.5 weight percent aluminum; about 1.5 to about 4.5 weight percent titanium; about 0.8 to about 3 weight percent niobium; about 14 to about 28 weight percent chromium; up to about 0.2 weight percent zirconium; about 10 to about 23 weight percent cobalt; about 1 to about 3 weight percent tungsten; about 0.05 to about 0.2 weight percent carbon, about 0.002 to about 0.012 weight percent boron; and about 40 to about 70 weight percent nickel. The atomic ratio of aluminum to titanium is at least about 0.5. The alloy is also substantially free of tantalum. Related processes and articles are also disclosed.

1 . A nickel-containing alloy comprising:
 about 1.5 to about 4.5 weight percent aluminum;   about 1.5 to about 4.5 weight percent titanium;   about 0.8 to about 3 weight percent niobium;   about 14 to about 28 weight percent chromium;   about 10 to about 23 weight percent cobalt;   about 1 to about 3 weight percent tungsten;   about 0.05 to about 0.2 weight percent carbon;   about 0.002 to about 0.012 weight percent boron; and   about 40 to about 70 weight percent nickel,   wherein the atomic ratio of aluminum to titanium is greater than about 1.0; and   wherein the alloy is substantially free of tantalum.   
     
     
         2 . The nickel-containing alloy of  claim 1 , wherein a sum of the amount of aluminum and titanium is about 2 to about 9 weight percent of the nickel-containing alloy. 
     
     
         3 . The nickel-containing alloy of  claim 1 , wherein the total amount of the aluminum, titanium, and niobium is about 2 to about 13 weight percent, based on the weight of the alloy. 
     
     
         4 . The nickel-containing alloy of  claim 1 , further comprising at least one element selected from the group consisting of zirconium, hafnium, rhenium, and ruthenium. 
     
     
         5 . The nickel-containing alloy of  claim 1 , containing an eta phase at a level of less than about 5 volume percent. 
     
     
         6 . A nickel-containing alloy comprising:
 about 1.6 to about 1.8 weight percent aluminum;   about 2.2 to about 2.4 weight percent titanium;   about 1.25 to 1.45 weight percent niobium;   about 22 to about 23 weight percent chromium;   about 18.5 to about 19.5 weight percent cobalt;   about 0.08 to about 0.12 weight percent carbon;   about 1.9 to about 2.1 weight percent tungsten;   about 0.002 to about 0.006 weight percent boron;   up to 0.01 weight percent zirconium;   with the remainder being nickel.   
     
     
         7 . A method for manufacturing an article, comprising:
 (a) casting an alloy into a mold, wherein the alloy comprises about 1.5 to about 4.5 weight percent aluminum; about 2.1 to about 4.5 weight percent titanium; about 0.8 to about 3 weight percent niobium; about 14 to about 24 weight percent chromium; about 10 to about 23 weight percent cobalt; about 1 to about 3 weight percent of an element selected from tungsten, rhenium, ruthenium, molybdenum, or a combination thereof; about 0.05 to about 0.2 weight percent of carbon; about 0.002 to about 0.012 weight percent of boron; and about 40 to about 70 weight percent nickel; and   (b) solidifying the casting.   
     
     
         8 . The method of  claim 7 , further comprising directionally solidifying the casting. 
     
     
         9 . The method of  claim 8 , wherein the casting is an equiaxed casting. 
     
     
         10 . The method of  claim 7 , further comprising heat-treating the casting at a temperature of about 1095 to about 1200° C. 
     
     
         11 . The method of  claim 10 , wherein the heat-treatment is conducted for a period of about 1 to about 4 hours. 
     
     
         12 . The method of  claim 7 , further comprising solution heat-treating the casting at a temperature of about 750 to about 850° C. 
     
     
         13 . A turbine component formed of a material comprising the alloy of  claim 1 .