HIGH ENTROPY ALLOY ARTICLE, METHOD FOR MANUFACTURING SAME, AND PRODUCT USING SAME

• US 20180363104A1
• Filed: 11/08/2016
• Published: 12/20/2018
• Est. Priority Date: 12/10/2015
• Status: Active Grant

• Current Assignee: Hitachi Metals (Thailand) Ltd.
• Original Assignee: Hitachi Metals (Thailand) Ltd.
• Inventors: FUJIEDA, Tadashi, KUWABARA, Kousuke, HIROTA, Mamoru, AOTA, Kinya, KATO, Takahiko, CHIBA, Akihiko, KOIZUMI, Yuichiro, YAMANAKA, Kenta
• Granted Patent: US 10,787,725 B2
• Time in Patent Office: Days
• CPC Class Codes: B22F 1/00 Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
• CPC Class Codes: B22F 1/05 Metallic powder characterised by the size or surface area of the particles
• CPC Class Codes: B22F 2301/15 Nickel or cobalt
• CPC Class Codes: B22F 2301/205 Titanium, zirconium or hafnium
• CPC Class Codes: B22F 2301/35 Iron
• CPC Class Codes: B22F 2304/10 Micron size particles, i.e. above 1 micrometer up to 500 micrometer
• CPC Class Codes: B22F 3/105 by using electric current other than for infrared radiant energy, laser radiation or plasma B22F3/11 takes precedence; by ultrasonic bonding B22F3/115 takes precedence
• CPC Class Codes: B22F 3/16 in successive or repeated steps
• CPC Class Codes: B22F 9/08 by casting, e.g. through sieves or in water, by atomising or spraying using electric discharge B22F9/14
• CPC Class Codes: B22F 9/082 atomising using a fluid using centrifugal force B22F9/10
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: B33Y 70/00 Materials specially adapted for additive manufacturing
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: C22C 1/0433 Nickel- or cobalt-based alloys
• CPC Class Codes: C22C 19/00 Alloys based on nickel or cobalt
• CPC Class Codes: C22C 30/00 Alloys containing less than 50% by weight of each constituent
• CPC Class Codes: F04D 17/10 for compressing or evacuating
• CPC Class Codes: F04D 29/02 Selection of particular materials for handling specific liquids F04D7/00 F04D23/001
• CPC Class Codes: F04D 29/023 especially adapted for elastic fluid pumps
• CPC Class Codes: F04D 29/28 for centrifugal or helico-centrifugal pumps for radial-flow or helico-centrifugal pumps
• CPC Class Codes: F04D 29/284 : for compressors

Abstract

An object of the invention is to provide: an HEA article that has excellent homogeneity in the alloy composition and microstructure as well as significant shape controllability, using an HEA with significant mechanical strength and high corrosion resistance; a method for manufacturing the HEA article; and a product using the HEA article. There is provided an HEA article comprising: Co, Cr, Fe, Ni, and Ti elements, each element in content of 5 to 35 atomic %; more than 0 atomic % to 8 atomic % of Mo %; and remainder substances of unavoidable impurities.

Claims

1. A high entropy alloy article comprising

Co, Cr, Fe, Ni, and Ti elements, each element in content of 5 atomic percent to 35 atomic percent,

more than 0 atomic percent to 8 atomic percent of Mo, and

remainder substances of unavoidable impurities, wherein

an intermetallic compound phase of acicular crystals is dispersedly precipitated in the matrix phase crystals of the high entropy alloy article.

2. The high entropy alloy article according to claim 1, wherein

the acicular crystals are dispersedly precipitated in a three-dimensional grid-like pattern.

3. The high entropy alloy article according to claim 1, wherein

chemical composition of the high entropy alloy comprises

atomic percent to 35 atomic percent of Co,atomic percent to 25 atomic percent of Cr,atomic percent to 25 atomic percent of Fe,atomic percent to 30 atomic percent of Ni, and

5 atomic percent to 15 atomic percent of Ti.

4. The high entropy alloy article according to claim 1, wherein

chemical composition of the high entropy alloy comprises

atomic percent to 33 atomic percent of Co,atomic percent to 23 atomic percent of Cr,atomic percent to 23 atomic percent of Fe,atomic percent to 28 atomic percent of Ni,

5 atomic percent to 10 atomic percent of Ti, and

1 atomic percent to 7 atomic percent of Mo.

5. The high entropy alloy article according to claim 1, wherein

chemical composition of said high entropy alloy comprises

atomic percent to 33 atomic percent of Co,atomic percent to 23 atomic percent of Cr,atomic percent to 23 atomic percent of Fe,atomic percent to 24 atomic percent of Ni,

5 atomic percent to 8 atomic percent of Ti, and

1 atomic percent to 3 atomic percent of Mo.

6. The high entropy alloy article according to claim 1, wherein

the intermetallic compound phase contains an Ni₃Ti phase.

7. The high entropy alloy article according to claim 1, wherein

tensile strength thereof is 1000 MPa or more and breaking elongation thereof is 3% or more.

8. The high entropy alloy article according to claim 1, wherein

the matrix phase crystal is a columnar crystal, and the crystal structure thereof contains a simple cubic crystal.

9. A method for manufacturing the high entropy alloy article according to claim 1, comprising the steps of:

mixing and melting raw materials for the high entropy alloy to form molten metal;

atomizing to form a high entropy alloy powder from the molten metal; and

additive manufacturing to form an additive manufactured article with a desired shape by means of a metal powder-based additive manufacturing method using the high entropy alloy powder.

10. The method for manufacturing the high entropy alloy article according to claim 9, wherein

the additive manufacturing step comprises:

a powder bed forming substep to form a powder bed of the high entropy alloy powder;

a powder bed calcination substep to form a calcined object of the powder bed by heating the entire powder bed; and

a local melting and solidified layer forming substep wherein

the calcined object is locally heated to form a minute molten pool of the high entropy alloy, and the minute alloy molten pools are moved and sequentially solidified by means of scanning of the local heating on the plane of the calcined object, thereby forming a solidified layer of the high entropy alloy.

11. A product using a high entropy alloy article,

said high entropy alloy article being the high entropy alloy article according to claim 1, and the product being an impeller of a fluid machine.

12. A centrifugal compressor incorporating the impeller according to claim 11.

13. The high entropy alloy article according to claim 2, wherein

chemical composition of the high entropy alloy comprises

atomic percent to 35 atomic percent of Co,atomic percent to 25 atomic percent of Cr,atomic percent to 25 atomic percent of Fe,atomic percent to 30 atomic percent of Ni, and

5 atomic percent to 15 atomic percent of Ti.

14. The high entropy alloy article according to claim 2, wherein

the intermetallic compound phase contains an Ni₃Ti phase.

15. The high entropy alloy article according to claim 2, wherein

tensile strength thereof is 1000 MPa or more and breaking elongation thereof is 3% or more.

16. The high entropy alloy article according to claim 2, wherein

the matrix phase crystal is a columnar crystal, and the crystal structure thereof contains a simple cubic crystal.

17. A product using a high entropy alloy article,

said high entropy alloy article being the high entropy alloy article according to claim 2, and the product being an impeller of a fluid machine.

18. A centrifugal compressor incorporating the impeller according to claim 17.