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.

近年来，随着人们对高熵合金 (HEA) 的激光增材制造 (LAM) 的兴趣日益浓厚，成分元素设计和工艺策略创新是克服不良微观结构和缺陷的主要方法。在这里，我们提出了一种新方法，一种新的熔池实时激光冲击调制 (LSMMP)，以获得熔池改性，以产生具有所需特性的 HEA。LSMMP 利用脉冲激光冲击由连续波激光引起的液体熔池，实现高性能 HEA 的非破坏性和实时调制。数值模拟揭示了LSMMP过程中熔池的对流机理，脉冲激光的介入促进熔池流动型将马兰戈尼效应转化为多对流环，加速熔池流动并抑制柱状晶体生长。实验结果表明了LSMMP过程中微观结构的演变规律。CrFeCoNi HEAs的微观结构经历了柱状等轴转变（CET），并获得了更高的硬度。激光冲击被证明是一种用于受控增材制造的有效原位调制工具。