Author(s): Lu, H (Lu, Heng); Zhang, XH (Zhang, Xiaohan); Liu, J (Liu, Jian); Zhao, SS (Zhao, Shusen); Lin, XC (Lin, Xuechun); Li, H (Li, Hui); Hu, YW (Hu, Yaowu)

Source: JOURNAL OF ALLOYS AND COMPOUNDS Volume: 925 Article Number: 166720 DOI: 10.1016/j.jallcom.2022.166720 Published: DEC 5 2022

Abstract: With growing interest in Laser Additive Manufacturing (LAM) of High-entropy alloys (HEAs) during most recent years, compositional elements design and process strategies innovation are primary methods to overcome undesirable microstructures and defects. Here we propose a new approach, a novel real-time laser shock modulation of melt pool (LSMMP) to obtain melt pool modifications for yielding HEAs with desired characteristics. LSMMP utilizes a pulsed laser shocking a liquid melt pool caused by a continuous wave laser, enabling non-destructive and real-time modulations for high-performance HEAs. The numerical simulation reveals the convection mechanism of the melt pool in the LSMMP process, and the intervention of the pulsed laser promotes melt pool flow type to convert the Marangoni effect into a multi-convective ring, which accelerates melt pool flow and inhibits columnar crystal growth. Experimental results show the evolution law of the microstructure in the LSMMP process. The microstructure of CrFeCoNi HEAs undergoes a Columnar-Equiaxed Transition (CET), and higher hardness is obtained. Laser shock is demonstrated to be an effective in-situ modulative tool for controlled additive manufacturing.(c) 2022 Elsevier B.V. All rights reserved.

Accession Number: WOS:000848429400002

ISSN: 0925-8388

eISSN: 1873-4669

Full Text: https://www.sciencedirect.com/science/article/pii/S0925838822031115?via%3Dihub