Titanium-based bulk amorphous matrix composite and method of fabricating thereof

Abstract

A Ti-based bulk amorphous matrix composite including a composition represented by Formula 1, in at %: Ti a Zr b Be c Cu d Ni e M f I g   Formula 1 where M is at least one of Nb and Ta, I is an impurity, and a, b, c, d, e, and f vary within the ranges 38≦a≦50, 11≦b≦18, 12≦c≦20, 6≦d≦10, 6≦e≦9, 1≦f≦20 and 0.01≦g≦0.5, with a+b+c+d+e+f+g=100.

What is claimed is: 
     
         1 . A Ti-based bulk amorphous matrix composite comprising a composition represented by Formula 1, in at %:
   Ti a Zr b Be c Cu d Ni e M f I g   Formula 1
   where M is at least one of Nb or Ta, I is an impurity, and a, b, c, d, e, and f vary within the ranges 38≦a≦50, 11≦b≦18, 12≦c≦20, 6≦d≦10, 6≦e≦9, 1≦f≦20 and 0.01≦g≦0.5, with a+b+c+d+e+f+g=100.   
     
     
         2 . The Ti-based bulk amorphous matrix composite of  claim 1 , wherein
 the composite has a structure comprising a crystalline phase with a dendritic morphology and of a size varying from about 0.01 μm to about 100 μm in an amorphous matrix.   
     
     
         3 . The Ti-based bulk amorphous matrix composite of  claim 2 , wherein
 elements for a formation of the amorphous matrix are titanium, zirconium, beryllium, copper and nickel.   
     
     
         4 . The Ti-based bulk amorphous matrix composite of  claim 2 , wherein
 elements for a formation of the crystalline phase are titanium, zirconium, and at least one of niobium and tantalum.   
     
     
         5 . The Ti-based bulk amorphous matrix composite of  claim 2 , wherein
 the composition for the formation of the amorphous matrix are defined according to the atomic ratio Ti/Zr less than about 2.8, Ti/Be less than about 2.25, and Ti/(Cu+Ni) less than about 2.37.   
     
     
         6 . The Ti-based bulk amorphous matrix composite of  claim 5 , wherein
 the composition are about 5 at %<Nb<about 20 at % and about 2 at %<Ta<about 8 at %.   
     
     
         7 . The Ti-based bulk amorphous matrix composite of  claim 1 , wherein
 the composite has a mechanical strength of about 1600 MPa to about 2000 MPa at room temperature and a density between about 6.1 g/cm 3  to about 8.0 g/cm 3 .   
     
     
         8 . The Ti-based bulk amorphous matrix composite of  claim 1 , wherein
 the composite has a value of hydrogen permeability between about 2×10 −8  mmol/m.s.Pa 0.5  to about 6 10 −8  mol/m.s.Pa 0.5  at about 350° C., depending on the composition   
     
     
         9 . The Ti-based bulk amorphous matrix composite of  claim 1 , wherein
 the composite has a corrosion current density under a hydrogen environment lower than stainless steel.   
     
     
         10 . A method of fabricating a Ti-based bulk amorphous matrix composite comprising:
 a vacuum suction casting technique and a vacuum squeeze casting technique,   wherein the composite comprising a composition represented by Formula 1, in at %:
   Ti a Zr b Be c Cu d Ni e M f I g   Formula 1
 
   where M is at least one of Nb and Ta, I is an impurity, and a, b, c, d, e, and f vary within the ranges 38≦a≦50, 11≦b≦18, 12≦c≦20, 6≦d≦10, 6≦e≦9, 1≦f≦20 and 0.01≦g≦0.5, with a+b+c+d+e+f+g=100.   
     
     
         11 . The method of  claim 10 , further comprising:
 annealing at temperature about 0.6Tg to about 0.8Tg, (Tg is the glass transition temperature expressed in Kelvin) for a predetermined time less than 1 hour to release eventual residual stresses.   
     
     
         12 . The method of  claim 10 , wherein
 the composite is deformed under a complex shape in a supercooled liquid region under a neutral and vacuum environment, and the supercooled liquid region, ΔT x , is a difference between a glass transition temperature, T g , and a crystallization temperature, T x .