Zirconium based bulk metallic glasses with hafnium

1. An article formed from a metallic glass composition having zirconium (Zr), hafnium (Hf), copper (Cu), aluminum (Al), at least one element from a group consisting of niobium (Nb) and titanium (Ti), and at least one element from a group consisting of nickel (Ni), iron (Fe), and cobalt (Co), the metallic glass composition having a formula of Zr a Hf b (Nb,Ti) c Cu d (Ni,Fe,Co) e Al f , wherein,

a is from about 35 to about 60;

b is from about 8 to about 20;

c is from about 0 to about 8;

d is from about 0 to about 40;

e is from about 0 to about 30; and

f is from about 5 to about 25, and wherein the article formed from the metallic glass composition has a minimum section thickness of about 5 mm to about 30 mm and contains an amorphous phase of the metallic glass composition, and wherein a ratio of Hf/(Ti+Nb) is from about 2 to about 5.

2. The article of claim 1 wherein:

a is from about 40 to about 60;

b is from about 8 to about 16;

c is from about 0 to about 6;

d is from about 0 to about 40;

e is from about 0 to about 20; and

f is from about 7 to about 15.

3. The article of claim 1 wherein:

a is from about 45 to about 55;

b is from about 8 to about 14;

c is from about 2 to about 5;

d is from about 0 to about 35;

e is from about 0 to about 20; and

f is from about 8 to about 11.

4. The article of claim 1 wherein:

a+b is from about 40 to about 55; and

d+e is from about 20 to about 50.

5. The article of claim 1 wherein:

a+b is from about 55 to about 70; and

d+e is from about 10 to about 40.

6. The article of claim 1 wherein the metallic glass composition has a formula of Zr 45 Hf 12 Nb 5 Cu 15.4 Ni 12.6 Al 10 or Zr 50 Hf 10 Nb 3 Cu 22 Fe 5 Al 10 .

7. The article of claim 1 wherein a bend ductility of the article is about 4%.

8. The article of claim 1 wherein a density of the article is about 7.0 to about 8.5 g/cm3.

9. The article of claim 8 wherein a section thickness of the article is about 5 mm to about 15 mm.

10. A metallic glass composition, comprising zirconium (Zr), hafnium (Hf), copper (Cu), aluminum (Al), at least one element from a group consisting of niobium (Nb) and titanium (Ti), and at least one element from a group consisting of nickel (Ni), iron (Fe), and cobalt (Co), wherein the metallic glass composition has a formula of Zr a Hf b (Nb,Ti) c Cu d (Ni,Fe,Co) e Al f , and wherein:

a is from about 35 to about 60;

b is from about 8 to about 20;

c is from about 0 to about 8;

d is from about 0 to about 40;

e is from about 0 to about 30; and

f is from about 5 to about 25, and wherein an article formed from the metallic glass composition has a minimum section thickness of about 5 mm to about 30 mm and contains an amorphous phase of the metallic glass composition, and wherein a ratio of Hf/(Ti+Nb) is from about 2 to about 5.

11. The metallic glass composition of claim 10 wherein:

a is from about 40 to about 60;

b is from about 8 to about 16;

c is from about 0 to about 6;

d is from about 0 to about 40;

e is from about 0 to about 20; and

f is from about 7 to about 15.

12. The metallic glass composition of claim 10 wherein:

a is from about 45 to about 55;

b is from about 8 to about 14;

c is from about 2 to about 5;

d is from about 0 to about 35;

e is from about 0 to about 20; and

f is from about 8 to about 11.

13. The metallic glass composition of claim 10 wherein:

a+b is from about 40 to about 55; and

d+e is from about 20 to about 50.

14. The metallic glass composition of claim 10 wherein:

a+b is from about 55 to about 70; and

d+e is from about 10 to about 40.

15. The metallic glass composition of claim 10 wherein the metallic glass composition has a formula of Zr 45 Hf 12 Nb 5 Cu 15.4 Ni 12.6 Al 10 or Zr 50 Hf 10 Nb 3 Cu 22 Fe 5 Al 10 .

16. A metallic glass composition comprising zirconium (Zr), hafnium (Hf), copper (Cu), aluminum (Al), at least one element from a group consisting of niobium (Nb) and titanium (Ti), and at least one element from a group consisting of nickel (Ni), iron (Fe), and cobalt (Co), wherein a concentration of the zirconium is from about 35 to about 60atomic percent, and wherein a concentration of the hafnium is from about 8 to about 20 atomic percent, and wherein the metallic glass composition is capable of being formed into an article having a minimum section thickness of about 5 mm to about 30 mm and contains an amorphous phase of the metallic glass composition, and wherein a ratio of Hf/(Ti+Nb) is from about 2 to about 5.

17. The metallic glass composition of claim 16 wherein a concentration of the at least one element from the group consisting of nickel (Ni), iron (Fe), and cobalt (Co) is about 0 to about 30 atomic percent.

18. The metallic glass composition of claim 16 wherein the metallic glass composition further includes at least one of tantalum (Ta), vanadium (V), beryllium (Be), palladium (Pd), or silver (Ag), and at least one of yttrium (Y), silicon (Si), or scandium (Sc).