# US 12,214,422 B2 · Method for preventing cracking of nickel-based superalloy fabricated by selective laser melting

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 12,214,422 B2
- Document ID: US12214422B2
- Status: Granted
- Kind: B2
- Application number: 17/490,355
- Filed: 2021-09-30
- Published: 2022-03-03
- Granted: 2025-02-04
- Earliest claimed: 2020-08-30
- Assignees: Central South University
- Applicants: Central South University
- Inventors: Zuming Liu; Bizhong Nong; Bing Wei; Yake Ren; Xu Zhou; Sizhe Lu; Bin Cao; Yongkang Ai
- Web page: https://patentgrep.com/patent/US12214422B2

## CPC

- B22F 10/28: Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM]
- B22F 9/082: {atomising using a fluid (using centrifugal force B22F9/10)}
- B22F 10/368: Temperature or temperature gradient, e.g. temperature of the melt pool
- B23K 26/0006: {taking account of the properties of the material involved (B23K26/32, B23K26/40 take precedence)}
- B23K 26/32: taking account of the properties of the material involved
- B23K 26/342: Build-up welding
- B33Y 10/00: Processes of additive manufacturing
- B33Y 70/00: Materials specially adapted for additive manufacturing
- C22C 19/056: {with the maximum Cr content being at least 10% but less than 20%}
- B22F 10/36: of energy beam parameters
- B22F 10/366: Scanning parameters, e.g. hatch distance or scanning strategy
- B22F 2009/0824: {with a specific atomising fluid}
- B22F 2009/0844: {in controlled atmosphere}
- B22F 2201/11: Argon
- B22F 2301/15: Nickel or cobalt
- B22F 2999/00: Aspects linked to processes or compositions used in powder metallurgy
- B33Y 50/02: for controlling or regulating additive manufacturing processes
- Y02P 10/25: Process efficiency
- B22F: WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER (making alloys by powder metallurgy C22C); APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B33Y: ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
- C22C: ALLOYS (treatment of alloys C21D, C22F)
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

A method for preventing cracking of nickel-based superalloy fabricated by selective laser melting (SLM) belongs to the field of additive manufacturing (AM). The method of preparing an as-built part with a high density, no crack defects, and good mechanical properties includes: reducing the content of elements Zr and B forming low melting point phase in a nickel-based superalloy, adjusting the total content of Al and Ti in the alloy to 4.5 wt % or below, and combining with the control of special SLM process parameters. The new method has the advantages of a reasonable component design, a simple preparation process, and good performance of the as-built part, and therefore is suitable for large-scale application.

## Claims

### Claim 1

A method for preventing cracking of a nickel-based superalloy fabricated by selective laser melting (SLM), comprising:
step 1: adjustment of alloy composition:
reducing a content of Zr to 0 wt % and a content of B to 0-0.02 wt % in the nickel-based superalloy, and adjusting a content of Al to 4.5 wt % or below and a content of Ti to 4.5 wt % or below in the nickel-based superalloy, to obtain a required nickel-based superalloy powder; and
step 2: SLM building:
preparing an as-built part under a protective atmosphere by an SLM building process using the required nickel-based superalloy powder as a raw material.

### Claim 2 (depends on 1)

The method according to claim 1, wherein
in the SLM building process, a substrate heating temperature is controlled to 150° C., a rotation angle between scanning layers is controlled to 67.5°, a laser input power is controlled to 300-350 W, a scanning speed is controlled to 750-850 mm/s, a scanning space is controlled to 0.11-0.13 mm, and a powder layer thickness is controlled to 30-40 μm.

### Claim 3 (depends on 1)

The method according to claim 1, wherein
in the SLM building process, a laser spot diameter is controlled to 0.12 mm; and
in the SLM building process, a snake scanning strategy is used for laser scanning.

### Claim 4 (depends on 1)

The method according to claim 1, wherein
in the step 2, the required nickel-based superalloy powder is prepared by argon atomization or by plasma rotating electrode process (PREP).

### Claim 5 (depends on 1)

The method according to claim 1, wherein
in the step 2, the protective atmosphere is an argon atmosphere.

### Claim 6 (depends on 1)

The method according to claim 1, wherein
the required nickel-based superalloy powder comprises the following components in percentage by mass:
Co: 20.6 wt %;
Cr: 13.0 wt %;
Mo: 3.8 wt %;
W: 2.1 wt %;
Al: 2.0 wt %;
Ti: 2.5 wt %;
Ta: 2.4 wt %;
Nb: 0.9 wt %;
Zr: 0 wt %;
B: 0.01 wt %;
C: 0.04 wt %; and
Ni: the balance;
the required nickel-based superalloy powder is prepared by argon atomization, and is sieved to obtain powder suitable for the SLM building; and
the SLM building is used, a substrate heating temperature is adjusted to 150° C., a rotation angle between scanning layers is set to 67°, a laser input power is set to 325 W, a scanning speed is set to 800 mm/s, a scanning space is set to 0.12 mm, a powder layer thickness is set to 30 μm, a laser spot diameter is selected as 0.12 mm, a snake scanning strategy is selected for laser scanning, and after argon gas is introduced, printing is started, to obtain an as-built part with a density of 99.35%, no cracks, and a tensile strength of 1145 MPa at room temperature on an X-Y plane.

### Claim 7 (depends on 1)

The method according to claim 1, wherein
the required nickel-based superalloy powder comprises the following components in percentage by mass:
Co: 8.5 wt %;
Cr: 16 wt %;
Mo: 1.75 wt %;
W: 2.6 wt %;
Al: 2.0 wt %;
Ti: 2.5 wt %;
Ta: 1.75 wt %;
Nb: 0.9 wt %;
Zr: 0 wt %;
B: 0.01 wt %;
C: 0.11 wt %; and
Ni: the balance;
the required nickel-based superalloy powder is prepared by argon atomization, and is sieved to obtain powder suitable for the SLM building; and
the SLM building is used, a substrate heating temperature is adjusted to 150° C., a rotation angle between scanning layers is set to 67°, a laser input power is set to 300 W, a scanning speed is set to 750 mm/s, a scanning space is set to 0.12 mm, a powder layer thickness is set to 30 μm, a laser spot diameter is selected as 0.12 mm, a snake scanning strategy is selected for laser scanning, and after argon gas is introduced, printing is started, to obtain an as-built part with a density of 99.28%, no cracks, and a tensile strength of 1127 MPa at room temperature on an X-Y plane.