文献类型：期刊文献

英文题名：Breaking the Strength-Ductility Trade-Off in an Additively Manufactured Titanium Alloy via Designing in-situ Lamellar Metastable Heterostructure

作者：Zhang, Kekang[1,2]; Lu, Tiwen[3]; Hu, Yixiong[1,2]; Chen, Hongyu[1,2]; Wang, Yonggang[1,2]; Wang, Di[4]; Zhang, Mina[5]; Liu, Yang[1,2]; Kosiba, Konrad[6]

机构：[1] Faculty of Mechanical Engineering & Mechanics, Ningbo University, Ningbo, 315211, China; [2] Key Laboratory of Impact and Safety Engineering, Ministry of Education, Ningbo University, Ningbo, 315211, China; [3] Key Laboratory of Pressure Systems and Safety, Ministry of Education, School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai, 200237, China; [4] School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou, 510640, China; [5] Research Centre for Laser Extreme Manufacturing, Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Ningbo, 315201, China; [6] Leibniz Institute for Solid State and Materials Research Dresden, Institute for Complex Materials, Helmholtzstr. 20, Dresden, 01069, Germany

年份：2024

外文期刊名：SSRN

收录：EI(收录号：20240478525)

语种：英文

外文关键词：Age hardening - Bond strength (materials) - High strength alloys - Iron alloys - Iron powder - Lamellar structures - Strain hardening - Tensile strength - Titanium powder metallurgy

摘要：The strength-ductility synergy in heterogeneous materials offers significant advantages, though their scalable and controlled production remains challenging. This study introduces a strategy for in-situ fabrication of a lamellar metastable titanium-based material via laser powder bed fusion of a powder blend consisting of Ti6Al4V (TC4) and 3 wt.% Fe powders. By periodic variation of the scanning velocity between layers, a heterogeneous lamellar titanium (HLT) microstructure is fabricated and it contains layers characterized by enhanced strength and ductility stemming from the peculiar Fe distribution and associated cooling rate variation. Consequently, the HLT achieves high tensile yield strength (1036 MPa) and ultimate strength (1347 MPa) without compromising uniform elongation (UE), surpassing most TC4 material and other titanium-based alloys. This high strength can be attributed to precipitation strengthening originating from the uniformly distributed nano-sized α and ω precipitates, while the high UE and work hardening arise from the accelerated stress-induced martensite (SIM) behavior and strong hetero-deformation induced (HDI) stress. The Fe addition reduces the Gibbs free energy of the resulting alloy, making high-velocity scanning layers more sensitive to the SIM behavior. A strain gradient between soft and hard layers evolves during loading and it further enhances the HDI strengthening and SIM behavior. Overall, the present HLT material demonstrates an outstanding combination of strength and ductility, providing insights for the fabrication of heterogeneous metastable materials. ? 2024, The Authors. All rights reserved.