Alloy with metallic glass and quasi-crystalline properties

• US 20020036034A1
• Filed: 09/25/2001
• Published: 03/28/2002
• Est. Priority Date: 09/25/2000
• Status: Active Grant

• Current Assignee: Johns Hopkins University
• Original Assignee: Johns Hopkins University
• Inventors: Hufnagel, Todd C., Xing, Li-Qian, Ramesh, Kaliat T.
• Granted Patent: US 6,692,590 B2
• Time in Patent Office: Days
• US Class Current: 148/561
• CPC Class Codes: C22C 45/10 with molybdenum, tungsten, niobium, tantalum, titanium, or zirconium or Hf as the major constituent

Abstract

An alloy is described that is capable of forming a metallic glass at moderate cooling rates and exhibits large plastic flow at ambient temperature. Preferably, the alloy has a composition of (Zr, Hf)_a Ta_bTi_cCu_dNi_eAl_f, where the composition ranges (in atomic percent) are 45≦a≦70, 3≦b≦7.5, 0≦c≦4, 3≦b+c≦10, 10≦d≦30, 0≦e≦20, 10≦d+e≦35, and 5≦f≦15. The alloy may be cast into a bulk solid with disordered atomic-scale structure, i.e., a metallic glass, by a variety of techniques including copper mold die casting and planar flow casting. The as-cast amorphous solid has good ductility while retaining all of the characteristic features of known metallic glasses, including a distinct glass transition, a supercooled liquid region, and an absence of long-range atomic order. The alloy may be used to form a composite structure including quasi-crystals embedded in an amorphous matrix. Such a composite quasi-crystalline structure has much higher mechanical strength than a crystalline structure.

Claims

1. An alloy exhibiting a plastic strain to failure in compression of more than about 1.5 percent at ambient temperature.

2. The alloy of claim 1, wherein the alloy exhibits a plastic strain to failure in compression of up to 7 percent at room temperature.

3. The alloy of claim 2, wherein the alloy exhibits an elastic strain of between about 2 and 2.5 percent.

4. The alloy of claim 2, wherein the alloy has a composition of (Zr, Hf)_a Ta_bTi_cCu_dNi_eAl_f, and wherein the composition ranges in atomic percent are 45≦

a≦

70, 3≦

b≦

7.5, 0≦

c≦

4, 3≦

b+c≦

10, 10≦

d≦

30, 0≦

e≦

20, 10≦

d+e≦

35 and 5≦

f≦

15.

5. The alloy of claim 4, wherein the alloy has a composition of Zr₅₉Ta₅Cu₁₈Ni₈Al₁₀.

6. The alloy of claim 4, wherein the alloy has a composition of Zr₅₆Ti₃Ta₂Cu₁₉Ni₉Al₁₁.

7. The alloy of claim 2, wherein the alloy has a composition of Zr_aTa_bTi_cCu_dNi_eAl_f, and wherein the composition ranges in atomic percent are 45≦

a≦

70, 2≦

b≦

7, 2≦

c≦

7, 4≦

b+c≦

25, 10≦

d≦

25, 5≦

e≦

15, and 5≦

f≦

15.

8. The alloy of claim 7, wherein the alloy has a composition of Zr₅₆Ti₃Ta₂Cu₁₉Ni₉Al₁₁.

9. A metallic glass having a thickness of at least one millimeter in its smallest dimension and exhibiting a plastic stain to failure in compression of greater than 1.5 percent and up to about 7 percent at room temperature.

10. The metallic glass of claim 9, wherein the metallic glass exhibits an elastic strain of between about 2 and 2.5 percent.

11. The metallic glass of claim 9, wherein the metallic glass comprises an alloy having a composition of (Zr, Hf)_a Ta_bTi_cCu_dNi_eAl_f, and wherein the composition ranges in atomic percent are 45≦

a≦

70, 3≦

b≦

7.5, 0≦

c≦

4. 3≦

b+c≦

10, 10≦

d≦

30, 0≦

e≦

20, 10≦

d+e≦

35, and 5≦

f≦

15.

12. The metallic glass of claim 11, wherein the alloy has a composition of Zr₅₉Ta₅Cu₁₈Ni₈Al₁₀.

13. The metallic glass of claim 11, wherein the alloy has a composition of Zr₅₆Ti₃Ta₂Cu₁₉Ni₉Al₁₁.

14. The metallic glass of claim 9, wherein the metalic glass comprises an alloy having a composition of Zr_aTa_bTi_cCu_dNi_eAl_f, and wherein the composition ranges in atomic percent are 45≦

a≦

70, 2≦

b≦

7, 2≦

c≦

7, 4≦

b+c≦

25, 10≦

d≦

25, 5≦

e≦

15, and 5≦

f≦

15.

15. The metallic glass of claim 14, wherein the alloy has a composition of Zr₅₆Ti₃Ta₂Cu₁₉Ni₉Al₁₁.

17. The method of claim 16, wherein said casting comprises copper mold casting.

18. The method of claim 16, wherein said casting comprises planar flow casting.

19. The method of claim 16, wherein said casting comprises injection die casting.

20. The method of claim 16, wherein said casting comprises suction casting.

21. The method of claim 16, wherein said casting comprises arc melting.

16. A method of forming a metallic glass exhibiting a plastic strain to failure in compression of more than about 1.5 percent at room temperature, the method comprising:

providing an alloy having a composition of (Zr, Hf)_a Ta_bTi_cCu_dNi_eAl_f, wherein the composition ranges in atomic percent are 45≦

a≦

70, 3≦

b≦

7.5, 0≦

c≦

4, 3≦

b+c≦

10, 10≦

d≦

30, 0≦

e≦

20, 10≦

d+e≦

35, and 5≦

f≦

15;

casting the alloy into an amorphous solid;

annealing the solid; and

cooling the solid at a rate of between about 1 K/s and about 1000 K/s.

22. A method of forming a metallic glass exhibiting a plastic strain to failure in compression of more than about 1.5 percent at ambient temperature, the method comprising:

providing an alloy having a composition of Zr_aTa_bTi_cCu_dNi_eAl_f, wherein the composition ranges in atomic percent are 45≦

a≦

70, 2≦

b≦

7, 2≦

c≦

7, 4≦

b+c≦

25, 10≦

d≦

25, 5≦

e≦

15, and 5≦

f≦

15;

casting the alloy into an amorphous solid;

annealing the solid; and

cooling the solid at a rate of between about 1 K/s and about 1000 K/s.

23. The method of claim 22, wherein said casting comprises copper mold casting.

24. The method of claim 22, wherein said casting comprises planar flow casting.

25. The method of claim 22, wherein said casting comprises injection die casting.

26. The method of claim 22, wherein said casting comprises suction casting.

27. The method of claim 22, wherein said casting comprises arc melting.