Pursued Strength-Ductility Synergy in Ni Superalloys Produced by Laser Powder Bed Fusion: Crystallographic Lamellar Versus Directionally Solidified Microstructure

作     者：Wang, Peng Liang, Jingjing Zhu, YuPing Yang, JunYing Zhou, Yizhou Sun, Xiaofeng Li, Jinguo 

作者机构：Shi-changxu Innovation Center for Advanced Materials Institute of Metal Research Chinese Academy of Sciences Shenyang110016 China School of Materials Science and Engineering University of Science and Technology of China Shenyang110016 China 

出 版 物：《SSRN》 

年 卷 期：2024年

核心收录：

主　　题：Textures 

摘      要：As a unique solidification microstructure of Ni superalloys produced by laser powder bed fusion (L-PBF), the crystallographic lamellar microstructure (CLM) exhibits a strong texture with and orientation, but in-depth mechanical properties studies remain lacking. In this study, comparative studies are conducted to reveal the unique deformation and strengthening mechanism of the CLM and non-CLM under room and high-temperature tensile conditions. However, substantial differences are observed in grain size, the number of grain boundaries, geometrical necessary dislocation (GND), elemental segregation, and crystallographic texture. The tensile results showed that the specimen with CLM exhibited an outstanding strength-ductility synergy due to the presence of high-proportioned texture and unique / boundary. The regularly distributed grains can serve as strong obstacles for slip bands and cracks propagating in grains. Moreover, the texture together with / boundary can elevate the local flow stresses and result in the activation of profuse deformation mechanisms, such as Planar slip bands, Stacking faults (SFs), and deformation twins. This work provides cross-scale insights into the deformation mechanisms and underscores the potential of CLM for developing high-temperature structural applications in Ni superalloy. © 2024, The Authors. All rights reserved.