Study on the effects of bilateral laser-assisted cutting on surface integrity and fatigue life of FeCoCrNiAl0.6 alloy

• Published in: Engineering failure analysis Vol. 166; p. 108921
• Main Authors: Zhang, Ping, Lin, Zhenyong, Zhang, Tengfei, Lan, Changyin, Jiang, Xiaomin
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.12.2024
• Subjects: Fatigue life; High-entropy alloy; Laser-assisted cutting; Residual stress; Surface quality; Fatigue life; Surface quality; Residual stress; High-entropy alloy; Laser-assisted cutting
• ISSN: 1350-6307
• DOI: 10.1016/j.engfailanal.2024.108921

•The mechanism of laser assisted cutting thermodynamic coupling was explored;•The competitive mechanism of laser assisted cutting heat softening and strengthening is explored;•The influence mechanism of bilateral laser assisted cutting on fatigue life was explored. This study investigates the impact of various cutting parameters in both unilateral and bilateral laser-assisted cutting processes on the surface integrity and fatigue life of FeCoCrNiAl0.6 high-entropy alloy. By utilizing ABAQUS/FE-SAFE simulations and conducting laser-assisted cutting and fatigue tensile tests, differences in surface quality and fatigue life cycles of FeCoCrNiAl0.6 alloy samples under different cutting scenarios were evaluated. The results indicate that in high-speed laser-assisted cutting, an increase in laser speed leads to a progressive decline in surface quality for both unilateral and bilateral methods. Nevertheless, at a laser speed of 4000 mm/s, optimal surface quality is achieved in both approaches, with the bilateral method consistently providing superior results across varying speeds. Regarding residual stress, unilateral laser-assisted cutting at 4000 mm/s produces a surface residual compressive stress of 532 MPa, which is twice as high as that observed at 10000 mm/s. The bilateral method shows a symmetric distribution of residual compressive stress, with peak values of 567 MPa and 528 MPa on the front and back surfaces, respectively. In terms of fatigue life, bilateral laser-assisted cutting demonstrates enhanced performance at 4000 mm/s, achieving a fatigue life cycle that is 4.72 times longer than that of the unilateral method. Overall, bilateral laser-assisted cutting improves the fatigue life of the material through symmetric thermal effects and higher residual compressive stress, particularly at lower laser speeds and optimal cutting depths.