Ni-base superalloy composition and method for SLM processing such Ni-base superalloy composition

Patent metadata

Field	Value
Publication number	US-11753705-B2
Application number	US-202117147831-A
Country	US
Kind code	B2
Filing date	Jan 13, 2021
Priority date	Jun 13, 2016
Publication date	Sep 12, 2023
Grant date	Sep 12, 2023

Abstract

A Ni-based superalloy composition to be used for powder-based additive manufacturing (AM) technology, such as selective laser melting (SLM) or electron beam melting (EBM). The cracking susceptibility during an AM process is considerably reduced by controlling the amount of elements, especially Hf, that form low-melting eutectics.

First claim

What is claimed is:

1. A Ni-based superalloy composition comprising:
a γ/γ′-microstructure, responsive to a heat treatment, that renders the Ni-based superalloy composition suitable for additive manufacturing (AM) of three dimensional articles with a γ/γ′-microstructure; and
first elements selected from a group of elements that are known to form low-melting eutectics, wherein an amount of each of the first elements is controlled to a level selected to reduce risk of crack formation during AM, and wherein the Ni-based superalloy composition is a modified version of CM247LC with a chemical composition of (in wt.-%): 9.5 W, 9.2 Co, 8.1 Cr, 5.6 Al, 3.2 Ta, 2.4 Hf, 0.7 Ti, 0.5 Mo, 0.075 C, 0.015 Zr, 0.015 B, and the balance Ni.

2. A Ni-based superalloy composition comprising:
a γ/γ′-microstructure, responsive to a heat treatment, that renders the Ni-based superalloy composition suitable for additive manufacturing (AM) of three dimensional articles with a γ/γ′-microstructure; and
first elements selected from a group of elements that are known to form low-melting eutectics, wherein an amount of each of the first elements is controlled to a level selected to reduce risk of crack formation during AM, and wherein the Ni-based superalloy composition is a modified version of MarM247 with a chemical composition of (in wt.-%): 10.0 W, 10.0 Co, 8.4 Cr, 5.5 Al, 3.0 Ta, 2.4 Hf, 1.0 Ti, 0.7 Mo, 0.15 C, 0.05 Zr, 0.015 B, and the balance Ni.

3. A method for SLM processing a Ni-based superalloy composition, the method comprising:
providing the Ni-based superalloy composition configured to form a γ/γ′-microstructure after a heat treatment and used for additive manufacturing of three dimensional articles with a γ/γ′-microstructure, wherein the amount of elements that form low-melting eutectics is controlled;
using the Ni-based superalloy composition in powder bed-based additive manufacturing technology and the Ni-based superalloy composition comprises first elements not bound in precipitates forming low-melting eutectics, wherein the first elements are Hf in an amount of at least 1.2 wt %;
providing protective atmosphere with O2 less than 1% with an O2 content in the powder being less than 800 ppm
performing the powder bed-based additive manufacturing technology.

4. The method according to claim 3 , wherein the protective atmosphere comprises O2 less than 0.6% with the O2 content in the powder being less than 500 ppm.

5. The method according to claim 4 , wherein the protective atmosphere comprises O2 less than 0.4% with the O2 content in the powder being less than 300 ppm.

6. The Ni-base superalloy composition according to claim 1 , wherein a ratio of Hf [at-%]/C [at-%] is greater than 1.3 and less than 2.3.

Assignees

• General Electric Technology Gmbh

Inventors

• Engeli Roman
• Etter Thomas
• Geiger Fabian

Classifications

• B22F10/00 Primary

  Additive manufacturing of workpieces or articles from metallic powder (apparatus or devices therefor B22F12/00) · CPC title

• C22C19/057 Primary

  with the maximum Cr content being less 10% · CPC title

• B33Y10/00

  Processes of additive manufacturing · CPC title

• B33Y70/00

  Materials specially adapted for additive manufacturing · CPC title

• B22F10/32

  of the atmosphere, e.g. composition or pressure in a building chamber · CPC title