Tantalum modified amorphous alloy

1. An amorphous alloy represented by the atomic formula:

(Zr,Hf) a (Al,Zn) b Ti e ,Nb f ,Ta g Y h (Cu x Fe y (Ni,Co) z ) d

wherein a ranges from 45 to 65 atomic %, b ranges from 5 to 15 atomic %, e and f each ranges from greater than 0 to 4.5 atomic %, g ranges from greater than 0 to 2 atomic %, h ranges from 0 to 0.5 atomic %, and the balance is d and incidental impurities wherein the Ti, Nb, and Ta comprise intentional alloying elements in the alloy and wherein e+f+g ranges from 3.5 to 7.5 atomic %, d times y is less than 10 atomic %, and x/z ranges from 0.5 to 2.

2. The alloy of claim 1 wherein g ranges from 1 to 2 atomic %.

3. The alloy of claim 1 wherein h ranges from 0.1 to 0.4 atomic %.

4. The alloy of claim 1 wherein Ti and Nb are both present and e+f is less than about 4 atomic %.

5. A bulk amorphous cast body comprising the alloy of claim 1 .

6. The cast body of claim 5 which is die cast.

7. An amorphous alloy consisting essentially of, in atomic %, about 54 to about 57% Zr, greater than 0 to about 4% Ti, greater than 0 to about 4% Nb, greater than 0 to about 2% Ta, about 8 to about 12% Al, about 14 to about 18% Cu, and about 12 to about 15% Ni, and 0 to about 0.5% Y wherein the Ti, Nb, and Ta comprise intentional alloying elements in the alloy.

8. The alloy of claim 7 wherein Ta is present in an amount from about 1 to about 2 atomic %.

9. The alloy of claim 7 having a Y content of 0.1 to 0.4 atomic % Y.

10. The alloy of claim 7 having a bulk oxygen impurity concentration of at least about 1000 ppm on atomic basis and a Y content of 0.1 to 0.4 atomic % Y.

11. A bulk amorphous cast body comprising the alloy of claim 7 .

12. The cast body of claim 11 which is die cast.

13. A method of making a bulk amorphous alloy casting, comprising

providing a molten alloy with a composition represented by the atomic formula:

(Zr,Hf) a (Al,Zn) b Ti e ,Nb f ,Ta g Y h (Cu x Fe y (Ni,Co) z ) d

wherein a ranges from 45 to 65 atomic %, b ranges from 5 to 15 atomic %, e and f each ranges from greater than 0 to 4.5 atomic %, g ranges from greater than 0 to 2 atomic %, h ranges from 0 to 0.5 atomic %, and the balance is d and incidental impurities wherein the Ti, Nb, and Ta comprise intentional alloying elements in the alloy and wherein e+f+g ranges from 3.5 to 7.5 atomic %, d times y is less than 10 atomic %, and x/z ranges from 0.5 to 2, and

and casting said alloy in a cavity to produce a bulk amorphous alloy casting.

14. The method of claim 13 wherein g is 1 to 2.

15. The method of claim 13 wherein h is 0.1 to 0.4.

16. The method of claim 13 wherein Ti and Nb are both present and e+f is less than about 4 atomic %.

17. A method of making a bulk amorphous alloy casting, comprising

providing a molten alloy with a composition consisting essentially of about 54 to about 57% Zr, greater than 0 to about 4% Ti, greater than 0 to about 4% Nb, greater than 0 to about 2% Ta, about 8 to about 12% Al, about 14 to about 18% Cu, and about 12 to about 15% Ni, and 0 to about 0.5% Y, and incidental impurities, wherein the Ti, Nb, and Ta comprise intentional alloying elements in the alloy, and

and casting said alloy in a cavity to produce a bulk amorphous alloy casting.

18. The method of claim 17 wherein said alloy has a Y content of about 0.1 to about 0.4 atomic % Y.

19. The method of claim 17 wherein said alloy has a bulk oxygen impurity concentration of at least about 1000 ppm on an atomic basis after said casting and a Y content of about 0.1 to about 0.4 atomic % Y.

20. The method of claim 17 wherein said alloy is die cast in said cavity.

21. The method of claim 18 wherein Ta is present in an amount from about 1 to about 2 atomic %.

22. An amorphous alloy represented by the atomic formula:

(Zr,Hf) a (Al,Zn) b Ti e ,Nb f ,Ta g Y h (Cu x Fe y (Ni,Co) z ) d

wherein a ranges from 45 to 65 atomic %, b ranges from 5 to 15 atomic %, e and f each is 1.5 atomic %, g is 1.5 atomic %, h ranges from 0 to 0.5 atomic %, and the balance is d and incidental impurities and wherein e+f+g is 4.5 atomic %, d times y is less than 10 atomic %, and x/z ranges from 0.5 to 2.