Copper-based alloys, processes for producing the same, and products formed therefrom

Abstract

Copper-manganese alloys, optionally with potentially other alloying elements, whose compositions are at or sufficiently near the congruent (minimum) melting point of the Cu—Mn system to substantially avoid dendritic growth during solidification. Processes for producing such alloys are also provided, as well as products produced from such alloys.

1 . A copper-manganese alloy containing copper and manganese in amounts at or sufficiently near the congruent melting point of the Cu—Mn alloy system to sufficiently avoid dendritic growth during solidification of the copper-manganese alloy to avoid the formation of microporosity attributable to dendritic growth. 
     
     
         2 . The copper-manganese alloy according to  claim 1 , wherein the copper-manganese alloy contains at least 25 weight percent and not more than 40 weight percent manganese. 
     
     
         3 . The copper-manganese alloy according to  claim 1 , wherein the copper-manganese alloy contains at least 32 weight percent and not more than 36 weight percent manganese. 
     
     
         4 . The copper-manganese alloy according to  claim 1 , wherein the copper-manganese alloy further contains one or more of iron, nickel, aluminum, silicon, tin and lead. 
     
     
         5 . The copper-manganese alloy according to  claim 1 , wherein the copper-manganese alloy does not contain lead. 
     
     
         6 . A process of producing a copper-manganese alloy containing copper and manganese in amounts at or sufficiently near the congruent melting point of the Cu—Mn alloy system to sufficiently avoid dendritic growth during solidification of the copper-manganese alloy to avoid the formation of microporosity attributable to dendritic growth, the process comprising combining copper and ferromanganese as a source of manganese. 
     
     
         7 . The process according to  claim 6 , wherein the ferromanganese contains about 75 to 80 weight percent manganese with the balance carbon, iron and incidental impurities. 
     
     
         8 . The process according to  claim 6 , wherein the combining step comprises reacting solid ferromanganese with copper that has not been deoxidized, and generating heat by oxidation of the carbon in the ferromanganese to melt and dissolve the ferromanganese. 
     
     
         9 . The process according to  claim 6 , wherein the copper-manganese alloy contains iron. 
     
     
         10 . The process according to  claim 6 , wherein the copper-manganese alloy contains at least 25 weight percent and not more than 40 weight percent manganese. 
     
     
         11 . The process according to  claim 6 , wherein the copper-manganese alloy contains at least 32 weight percent and not more than 36 weight percent manganese. 
     
     
         12 . The process according to  claim 6 , wherein the copper-manganese alloy further contains one or more of iron, nickel, aluminum, silicon, tin and lead. 
     
     
         13 . The process according to  claim 6 , wherein the copper-manganese alloy does not contain lead. 
     
     
         14 . An article formed by solidifying a copper-manganese alloy containing copper and manganese in amounts at or sufficiently near the congruent melting point of the Cu—Mn alloy system to sufficiently avoid dendritic growth during solidification of the copper-manganese alloy to avoid the formation of microporosity in the article attributable to dendritic growth. 
     
     
         15 . The article according to  claim 14 , wherein the copper-manganese alloy contains at least 25 weight percent and not more than 40 weight percent manganese. 
     
     
         16 . The article according to  claim 14 , wherein the copper-manganese alloy contains at least 32 weight percent and not more than 36 weight percent manganese. 
     
     
         17 . The article according to  claim 14 , wherein the copper-manganese alloy further contains one or more of iron, nickel, aluminum, silicon, tin and lead. 
     
     
         18 . The article according to  claim 14 , wherein the copper-manganese alloy does not contain lead. 
     
     
         19 . The article according to  claim 14 , wherein the article is a casting. 
     
     
         20 . The article according to  claim 14 , wherein the article is a plumbing valve or fitting.