Effect of Ta Content on the Microstructure and Mechanical Properties of Laser Additive Manufactured Nickel-Based Superalloys

Alloys with low Ti/Al content exhibit insufficient strength,while those with high Ti/Al content are prone to cracking during laser additive manufacturing.To achieve a balance between high γ′ phase volume fraction and low crack susceptibility,this study proposed an alloy design strategy: appropriatel...

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Bibliographic Details
Main Author: GUO Liangliang, WU Wenxing, YANG Tong, CHEN Pinghu, JIN Xuming, ZHU Tao, ZOU Xinchang, QIU Changjun
Format: Article
Language:zho
Published: Editorial Department of Materials Protection 2025-07-01
Series:Cailiao Baohu
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Online Access:http://www.mat-pro.com/fileup/1001-1560/PDF/20250706.pdf
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Summary:Alloys with low Ti/Al content exhibit insufficient strength,while those with high Ti/Al content are prone to cracking during laser additive manufacturing.To achieve a balance between high γ′ phase volume fraction and low crack susceptibility,this study proposed an alloy design strategy: appropriately reducing Ti/Al content while increasing Ta content based on the high-Ti/Al IN738LC alloy.Based on this design strategy,the microstructures and properties of four laser additive as-deposited samples with different Ta contents before and after solid solution treatment and aging treatment were studied.Results showed that with increasing Ta content,the as-deposited samples exhibited grain refinement and a higher γ′ phase fraction.The tensile strength and yield strength of both as-deposited and heat-treated samples increased as the Ta content increased,while their ductility decreased and cracking susceptibility intensified.When the mass fraction of Ta in the heat-treated samples reached 5%,η-phase precipitation occurred.At 7%Ta content,excessive η-phase formation led to brittle fracture surfaces in tensile specimens.Moreover,the sample with 5%Ta exhibited an optimal strength-ductility combination: at 25 ℃,yield strength of 962 MPa,ultimate tensile strength of 1 212 MPa,and elongation of 11.0%;while at 900 ℃,yield strength of 410 MPa,ultimate tensile strength of 486 MPa,and elongation of 6.1%.Generally,through optimization of Al,Ti and Ta contents,this study successfully developed a γ′-phase strengthened laser additive manufactured nickel-based superalloy.The alloy achieved an optimal balance between high γ′-phase volume fraction and low cracking susceptibility,demonstrating excellent comprehensive mechanical properties,and these findings provided valuable insights for the compositional design of laser additive manufactured nickel-based superalloys.
ISSN:1001-1560