Laser powder bed fusion of a Ni3Al-based intermetallic alloy with tailored microstructure and superior mechanical performance

Mingyu Liu; Jiang Wang; Tao Hu; Songzhe Xu; Sansan Shuai; Weidong Xuan; Shuo Yin; Chaoyue Chen; Zhongming Ren

Advanced Powder Materials (Feb 2024)

Laser powder bed fusion of a Ni3Al-based intermetallic alloy with tailored microstructure and superior mechanical performance

Mingyu Liu,
Jiang Wang,
Tao Hu,
Songzhe Xu,
Sansan Shuai,
Weidong Xuan,
Shuo Yin,
Chaoyue Chen,
Zhongming Ren

Affiliations

Mingyu Liu: State Key Laboratory of Advanced Special Steels, School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
Jiang Wang: State Key Laboratory of Advanced Special Steels, School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China; Corresponding author.
Tao Hu: State Key Laboratory of Advanced Special Steels, School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
Songzhe Xu: State Key Laboratory of Advanced Special Steels, School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
Sansan Shuai: State Key Laboratory of Advanced Special Steels, School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
Weidong Xuan: State Key Laboratory of Advanced Special Steels, School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
Shuo Yin: Parsons Building, Department of Mechanical, Manufacturing and Biomedical Engineering, Trinity College Dublin, The University of Dublin, Dublin, Ireland; College of Mechanical Engineering, Yangzhou University, Yangzhou 225127, China
Chaoyue Chen: State Key Laboratory of Advanced Special Steels, School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China; Corresponding author.
Zhongming Ren: State Key Laboratory of Advanced Special Steels, School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China

Journal volume & issue: Vol. 3, no. 1
p. 100152

Abstract

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Ni3Al-based alloys are excellent candidates for the structural materials used for turbine engines due to their excellent high-temperature properties. This study aims at laser powder bed fusion and post-hot isostatic pressing (HIP) treatment of Ni3Al-based IC-221 M alloy with a high γ′ volume fraction. The as-built samples exhibits unavoidable solidification cracking and ductility dip cracking, and the laser parameter optimization can reduce the crack density to 1.34 mm/mm2. Transmission electron microscope (TEM) analysis reveals ultra-fine nanoscale γ′ phases in the as-built samples due to the high cooling rate during rapid solidification. After HIP treatment, a fully dense structure without cracking defects is achieved, which exhibits an equiaxed structure with grain size ∼120–180 μm and irregularly shaped γ′ precipitates ∼1–3 μm with a prominently high fraction of 86%. The room-temperature tensile test of as-built samples shows a high ultimate tensile strength (σUTS) of 1039.7 MPa and low fracture elongation of 6.4%. After HIP treatment, a significant improvement in ductility (15.7%) and a slight loss of strength (σUTS of 831.7 MPa) are obtained by eliminating the crack defects. Both the as-built and HIP samples exhibit retained high σUTS values of 589.8 MPa and 786.2 MPa, respectively, at 900 °C. The HIP samples exhibita slight decrease in ductility to ∼12.9%, indicating excellent high-temperature mechanical performance. Moreover, the abnormal increase in strength and decrease in ductility suggest the critical role of a high γ′ fraction in cracking formation. The intrinsic heat treatment during repeating thermal cycles can induce brittleness and trigger cracking initiation in the heat-affected zone with notable deteriorating ductility. The results indicate that the combination of LPBF and HIP can effectively reduce the crack density and enhance the mechanical properties of Ni3Al-based alloy, making it a promising material for high-temperature applications.

Published in Advanced Powder Materials

ISSN: 2772-834X (Online)
Publisher: KeAi Communications Co. Ltd.
Country of publisher: China
LCC subjects: Technology: Mining engineering. Metallurgy
Website: https://www.keaipublishing.com/en/journals/advanced-powder-materials/

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