Creep- and oxidation-resistant molybdenum superalloy

Abstract

The present invention relates to a quaternary or multinary molybdenum alloy for the production of structural components, in particular of vanes of a turbomachine having the main constituents molybdenum, silicon, boron and titanium, which, as minor alloying elements, additionally comprises at least one of iron and yttrium.

What is claimed is: 
     
         1 . A molybdenum alloy for the production of structural components, wherein the alloy comprises molybdenum, silicon, boron and titanium as main constituents and further comprises one or both of iron and yttrium as minor alloying elements. 
     
     
         2 . The molybdenum alloy of  claim 1 , wherein the alloy further comprises one or more of zirconium, niobium and tungsten as additional minor alloying elements. 
     
     
         3 . The molybdenum alloy of  claim 1 , wherein the alloy comprises from 0.1 to 5 at. % of each of iron and/or yttrium. 
     
     
         4 . The molybdenum alloy of  claim 1 , wherein the alloy comprises from 0.3 to 3 at. % of each of iron and/or yttrium. 
     
     
         5 . The molybdenum alloy of  claim 1 , wherein the alloy comprises from 0.5 to 3 at. % of iron and from 0.3 to 2 at. % of yttrium. 
     
     
         6 . The molybdenum alloy of  claim 5 , wherein the alloy comprises from 0.8 to 1.6 at. % of iron and from 0.5 to 1.5 at. % of yttrium. 
     
     
         7 . The molybdenum alloy of  claim 2 , wherein the alloy comprises less than or equal to 5 at. % of zirconium. 
     
     
         8 . The molybdenum alloy of  claim 2 , wherein the alloy comprises less than or equal to 20 at. % of niobium. 
     
     
         9 . The molybdenum alloy of  claim 2 , wherein the alloy comprises less than or equal to 8 at. % of tungsten. 
     
     
         10 . The molybdenum alloy of  claim 1 , wherein the alloy comprises from 9 to 15 at. % of silicon, from 5 to 9 at. % of boron, and from 25 to 33 at. % of titanium. 
     
     
         11 . The molybdenum alloy of  claim 10 , wherein the alloy comprises from 13 to 14 at. % of silicon, from 5 to 6 at. % of boron, and from 26 to 29 at. % of titanium. 
     
     
         12 . The molybdenum alloy of  claim 1 , wherein the alloy is formed exclusively by molybdenum, silicon, boron, titanium, iron, yttrium, niobium, tungsten, zirconium. 
     
     
         13 . The molybdenum alloy of  claim 1 , wherein the alloy is formed exclusively by molybdenum, silicon, boron, titanium, iron, yttrium. 
     
     
         14 . The molybdenum alloy of  claim 1 , wherein the alloy comprises from 35 to 66 at. % of molybdenum. 
     
     
         15 . The molybdenum alloy of  claim 1 , wherein a true density of the alloy is less than or equal to 9 g/cm 3 . 
     
     
         16 . The molybdenum alloy of  claim 1 , wherein the alloy comprises a matrix of a molybdenum mixed crystal and one or more silicide phases. 
     
     
         17 . The molybdenum alloy of  claim 16 , wherein the one or more silicide phases comprise (Mo,Ti) 5 Si 3  and/or (Mo,Ti) 5 SiB 2 . 
     
     
         18 . The molybdenum alloy of  claim 16 , wherein the alloy comprises from 15 to 35 vol. % of (Mo,Ti) 5 Si 3 , from 15 to 35 vol. % of (Mo,Ti) 5 SiB 2 , and from 1 to 20 vol. % of one or more minor phases. 
     
     
         19 . The molybdenum alloy of  claim 16 , wherein the alloy comprises from 45 to 55 vol. % of molybdenum mixed crystal. 
     
     
         20 . A component of a turbomachine, wherein the component is formed of the molybdenum alloy of  claim 1 .