Very high strength copper-titanium alloy with improved formability in the solution annealed temper

Abstract

A copper-titanium alloy includes, by weight, at least 90% copper, from 5 to 7% titanium and from 0.25 to 0.5% iron. It has excellent ductility at the solution-annealed temper and high yield strength after an ageing treatment.

1 . A copper-titanium alloy comprising, by weight, at least 90% copper, from 5 to 7% titanium and from 0.25 to 0.5% iron. 
     
     
         2 . The copper-titanium alloy as claimed in  claim 1 , wherein the content of titanium, by weight, is at least 5.2%. 
     
     
         3 . The copper-titanium alloy as claimed in  claim 1 , wherein the content of titanium, by weight, is at least 5.5%. 
     
     
         4 . The copper-titanium alloy as claimed in  claim 1 , wherein the content of titanium, by weight, is at least 6%. 
     
     
         5 . The copper-titanium alloy as claimed in  claim 1 , wherein the content of titanium, by weight, is at most 6.5%. 
     
     
         6 . The copper-titanium alloy as claimed in  claim 1 , wherein the content of iron, by weight, is at most 0.4%. 
     
     
         7 . The copper-titanium alloy as claimed in  claim 1 , wherein the content of iron, by weight, is at most 0.35%. 
     
     
         8 . The copper-titanium alloy as claimed in  claim 1 , including only copper, titanium, iron and unavoidable impurities. 
     
     
         9 . The copper-titanium alloy according to as claimed in  claim 1 , further comprising aluminum at a content of not more than 1.4% by weight. 
     
     
         10 . The copper-titanium alloy as claimed in  claim 1 , further comprising, by weight, from 0.1 to 1.4% aluminum. 
     
     
         11 . The copper-titanium alloy as claimed in  claim 1 , further comprising aluminum at a content of from 0.1 to 0.7%. 
     
     
         12 . The copper-titanium alloy as claimed in  claim 9 , including only copper, titanium, iron, aluminum and unavoidable impurities. 
     
     
         13 . The copper-titanium alloy as claimed in  claim 1 , comprising no silver or comprising silver at a content of not more than 0.08%. 
     
     
         14 - 16 . (canceled) 
     
     
         17 . The copper-titanium alloy as claimed in  claim 10 , including only copper, titanium, iron, aluminum and unavoidable impurities. 
     
     
         18 . A Bourdon tube made of the copper-titanium alloy as claimed in  claim 1 . 
     
     
         19 . A part of a timepiece made of the copper-titanium alloy as claimed in  claim 1 .