Self-healing cobalt based alloys and manufacturing method for the same

Patent metadata

Field	Value
Publication number	US-2021395864-A1
Application number	US-202017070051-A
Country	US
Kind code	A1
Filing date	Oct 14, 2020
Priority date	Jun 22, 2020
Publication date	Dec 23, 2021
Grant date	—

Abstract

The present disclosure provides a cobalt-based alloy having self-healing property. The cobalt-based alloy has composition as below: [[CoaTibCr100-a-b]1-0.01cSc]1-0.01dHd (57≤a≤92.5 at. %, 6≤b≤33 at. %, a+b<100, S means strengthening solute elements, 0<c≤20 at. %, H means healing solute elements, and 0<d≤2 at. %), wherein self-healing function is implemented by the healing solute elements.

First claim

What is claimed is:

1 . A cobalt-based alloy having self-healing property, the cobalt-based alloy having composition as below:
[[Co a Ti b Cr 100-a-b ] 1-0.01c S c ] 1-0.01d H d (57≤a≤92.5 at. %, 6≤b≤33 at. %, a+b<100, S means strengthening solute elements, 0<c≤20 at. %, H means healing solute elements, and 0<d≤2 at. %), wherein self-healing function is implemented by the healing solute element.

2 . The cobalt-based alloy of claim 1 , comprising both of γ and γ′ phases as constituent phases.

3 . The cobalt-based alloy of claim 2 , wherein upon the deformation of the alloy, the healing solute elements are diffused and segregated into defect sites to strengthen deformed portion, thereby delaying crack formation and propagation, leading to the implementation of self-healing.

4 . The cobalt-based alloy of claim 2 , wherein the fraction of the γ′ phase is less than 50%.

5 . The cobalt-based alloy of claim 2 , wherein the size of the γ′ phase is less than 1 μm.

6 . The cobalt-based alloy of claim 2 , further comprising secondary precipitates of the γ′ phase having a size of tens of nanometers.

7 . The cobalt-based alloy of claim 1 , wherein the strengthening solute elements comprise at least one selected from the group consisting of Mo, Hf, Ta, and W.

8 . The cobalt-based alloy of claim 1 , wherein the healing solute elements comprise at least one selected from the group consisting of B, C, N, O, P, and S.

9 . The cobalt-based alloy of claim 1 , wherein when 6≤b≤11 (at. %), 70≤a≤86.5 (at. %), 0<c≤0.5b (at. %), and 0<d≤0.5 (at. %) (provided that a+b<100).

10 . The cobalt-based alloy of claim 1 , wherein when 11<b≤16 (at. %), 80≤a≤86.5 (at. %), 0<c≤0.5b (at. %), 0<d≤0.5 (at. %) (a+b<100).

11 . A method for manufacturing a cobalt-based alloy having self-healing property, the method comprising:
preparing raw materials constituting the alloy of claim 1 ; melting the raw materials to prepare an alloy; subjecting the alloy to solution treatment; subjecting the alloy to aging treatment; and cooling the alloy, wherein the alloy comprises γ and γ′ phases together.

12 . The method of claim 11 , wherein the solution treatment is carried out at temperature of 1050-1400° C. for 1-1000 hours.

13 . The method of claim 11 , wherein the aging treatment is carried out at temperature of 700-1000° C. for 1-1000 hours.

14 . The method of claim 11 , wherein the fraction of the γ′ phase is less than 50% by the aging treatment.

15 . The method of claim 11 , wherein secondary precipitates of the γ′ phase are additionally formed during the cooling step.

Assignees

• Seoul Nat Univ R&Db Foundation

Inventors

• Park Eun Soo
• Yoon Kook Noh
• Lee Jung Soo
• Yoo Geun Hee
• Kim Ji Young

Classifications

• Y02E30/10

  Nuclear fusion reactors · CPC title

• C22F1/10

  of nickel or cobalt or alloys based thereon · CPC title

• C22C19/07 Primary

  based on cobalt · CPC title

• C22F1/16

  of other metals or alloys based thereon · CPC title

• C22C1/02

  by melting {(C22C1/1036 takes precedence)} · CPC title