Bulk nickel-chromium-phosphorus glasses bearing niobium and boron exhibiting high strength and/or high thermal stability of the supercooled liquid

• US 10,000,834 B2
• Filed: 11/13/2014
• Issued: 06/19/2018
• Est. Priority Date: 02/25/2014
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc., Glassimetal Technology Inc.
• Inventors: Na, Jong Hyun, Launey, Maximilien, Duggins, Danielle, Abarca, Oscar, Demetriou, Marios D., Johnson, William L.
• Primary Examiner(s): WYSZOMIERSKI, GEORGE P
• Application Number:
  US14/540,815
• Publication Number:
  US 20150240336A1
• Time in Patent Office: 1,314 Days
• Field of Search: None
• CPC Class Codes: C22C 1/11 Making amorphous alloys
• CPC Class Codes: C22C 45/04 with nickel or cobalt as the major constituent

Abstract

Ni—Cr—Nb—P—B alloys and metallic glasses are provided, where Nb and B are varied such as to achieve alloys with good glass forming ability that form metallic glasses which may exhibit unexpectedly high strength and/or high thermal stability of the supercooled liquid. Specifically, the alloys of the current disclosure are capable of forming metallic glasses and have critical rod diameters of at least 3 mm, while the metallic glasses exhibit yield strength greater than 2550 MPa and stability of the supercooled liquid of at least 45° C.

Claims

1. An alloy capable of forming a metallic glass represented by the following formula (subscripts a, b, c, and d denote atomic percentages):

Ni<sub>(100−

a−

b−

c−

d)</sub>Cr_aNb_bP_cB_d

wherein;

a ranges from 7 to 11, b ranges from 4.5 to 5.5, c ranges from 13 to 16, d ranges from 4.5 to 5.5; and

wherein the critical rod diameter of the alloy is at least 3 mm.

2. The alloy according to claim 1 wherein the metallic glass has a yield strength greater than 2550 MPa.

3. The alloy according to claim 1 wherein the metallic glass has Vickers hardness of at least 742 Kgf/mm².

4. The alloy according to claim 1 wherein up to 1 atomic percent of P is substituted by Si, Sn or combinations thereof.

5. A metallic glass comprising an alloy according to claim 1.

6. An alloy capable of forming a metallic glass represented by the following formula (subscripts a, b, c, and d denote atomic percentages):

Ni<sub>(100−

a−

b−

c−

d)</sub>Cr_aNb_bP_cB_d

wherein a, b, and c are determined according to the following equations;

a=a₁+a₂·

d

c=c₁+c₂·

d

wherein

b=b₁·

d, d ranges from 4.5 to 5.5, a₁ ranges from 10.5 to 12.5, a₂ ranges from −

1.1 to −

0.9, b₁ ranges from 0.9 to 1.1, c₁ ranges from 19 to 20, c₂ ranges from −

1.1 to −

0.9;

or

b=b₁+b₂·

d, d ranges from 4.5 to 6.5, a₁ ranges from 6 to 8, a₂ ranges from 0.3 to 0.55, b₁ ranges from 4 to 5, b₂ ranges from −

0.55 to −

0.3, c₁ ranges from 19 to 20, c₂ ranges from −

1.1 to −

0.9; and

wherein the critical rod diameter of the alloy is at least 3 mm.

7. The alloy according to claim 6 wherein d ranges from 4.5 to 6.5, a₁ ranges from 6 to 8, a₂ ranges from 0.3 to 0.55, b₁ ranges from 4 to 5, b₂ ranges from −

0.55 to −

0.3, c₁ ranges from 19 to 20, c₂ ranges from −

1.1 to −

0.9;

wherein the critical rod diameter of the alloy is at least 3 mm, and wherein the thermal stability of the supercooled liquid of the metallic glass, defined as the difference between T_x and T_g measured at a scan rate of 20°

C./min, is at least 45°

C.

8. The alloy according to claim 7 wherein up to 1 atomic percent of P is substituted by Si, Sn or combinations thereof.

9. A metallic glass comprising an alloy according to claim 7.

10. The metallic glass of claim 9 wherein the notch toughness is at least 55 MPa m^1/2.

11. The metallic glass of claim 10 wherein the notch toughness is at least 70 MPa m^1/2.

12. The alloy according to claim 6 wherein d ranges from 4.5 to 5.5, a₁ ranges from 6 to 8, a₂ ranges from 0.45 to 0.55, b₁ ranges from 4 to 5, b₂ ranges from −

0.55 to −

0.45, c₁ ranges from 19 to 20, c₂ ranges from −

1.1 to −

0.9;

wherein critical rod diameter of the alloys is at least 5 mm, and wherein the thermal stability of the supercooled liquid of the metallic glass, defined as the difference between T_x and T_g measured at a scan rate of 20°

C./min, is at least 50°

C.

13. An alloy capable of forming a metallic glass having composition selected from a group consisting of Ni₆₉Cr₇Nb_4.5P₁₅B_4.5, Ni₆₉Cr_6.875Nb_4.675P_14.875B_4.675, Ni₆₉Cr_6.75Nb_4.75P_14.75B_4.75, Ni₆₉Cr_6.675Nb_4.875P_14.675B_4.875, Ni₆₉C_6.5Nb₅P_14.5B₅, Ni₆₉Cr_6.375Nb_5.125P_14.375B_5.125, Ni₆₉Cr_6.25Nb_5.25P_14.25B_5.25, Ni₆₉Cr_6.125Nb_5.375P_14.125B_5.375, Ni₆₉Cr_9.5Nb₂P_14.5B₅, Ni₆₉Cr_9.75Nb_1.75P₁₄B_5.5, and Ni₆₉Cr_10.25Nb_1.25P₁₃B_6.5.