Tian Xinyu, Wang Chao, Zhang Hongyang, Gao Junfeng, Huang Hu, Yan Jiwang
Key Laboratory of CNC Equipment Reliability, Ministry of Education, School of Mechanical and Aerospace Engineering, Jilin University, Changchun 130022, China.
Department of Mechanical Engineering, Faculty of Science and Technology, Keio University, Yokohama 223-8522, Japan.
Materials (Basel). 2024 Jul 27;17(15):3728. doi: 10.3390/ma17153728.
Laser bending forming, as a flexible and die-less forming approach, facilitates the three-dimensional shaping of sheets through the generation of thermal stress via laser-material interaction. In this study, the bending forming characteristics of CoCrFeMnNi high-entropy alloy sheets induced by nanosecond pulse laser irradiation were systematically investigated. The effects of parameters including laser power, scanning speed, number of scans, scanning interval, and sheet size on the bending angle, cross-sectional morphology, and hardness were studied in detail under both the laser single-line and multi-line scanning modes. The experimental results confirmed the effectiveness of nanosecond pulse laser irradiation for achieving accurate formation of CoCrFeMnNi sheets, with the successful fabrication of J, L, and U-shaped metal components. Apart from the forming ability, the cross-sectional hardness was significantly increased due to the grain refinement effect of nanosecond pulse laser irradiation. Furthermore, employing the laser single-line scanning mode enabled the effective rectification of overbending parts, showcasing complete recovery for small-angle overbending, and a remarkable 91% recovery for larger-angle overbending. This study provides an important basis for the bendability of CoCrFeMnNi sheets by laser forming and elucidates the evolution of the microstructure and mechanical properties in the bending region.
激光弯曲成形作为一种灵活的无模成形方法，通过激光与材料的相互作用产生热应力，促进板材的三维成形。在本研究中，系统地研究了纳秒脉冲激光辐照诱导的CoCrFeMnNi高熵合金板材的弯曲成形特性。在激光单线和多线扫描模式下，详细研究了激光功率、扫描速度、扫描次数、扫描间隔和板材尺寸等参数对弯曲角度、横截面形貌和硬度的影响。实验结果证实了纳秒脉冲激光辐照对于实现CoCrFeMnNi板材精确成形的有效性，成功制造出了J形、L形和U形金属部件。除了成形能力外，由于纳秒脉冲激光辐照的晶粒细化作用，横截面硬度显著提高。此外，采用激光单线扫描模式能够有效矫正过度弯曲部分，小角度过度弯曲实现了完全恢复，大角度过度弯曲恢复率高达91%。本研究为CoCrFeMnNi板材的激光弯曲成形性能提供了重要依据，并阐明了弯曲区域微观结构和力学性能的演变。
