Enhanced arc-acoustic interaction by stepped-plate radiator in ultrasonic wave-assisted GTAW

• Published in: Journal of materials processing technology Vol. 262; pp. 19 - 31
• Main Authors: Wang, Jianfeng, Sun, Qingjie, Teng, Junbo, Jin, Peng, Zhang, Tao, Feng, Jicai
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.12.2018; Elsevier BV
• Subjects: Acoustic emission; Acoustic field; Arc-acoustic interaction; Comparative analysis; Configurations; Curve fitting; Gas tungsten arc welding; Grain refinement; GTA welding; Microstructure; Power ultrasound; Pressure; Radiators; Simulation; Stepped-plate radiator; Ultrasonic vibration; Weld metal; Welding; Stepped-plate radiator; Acoustic field; Arc-acoustic interaction; GTA welding; Power ultrasound
• ISSN: 0924-0136; 1873-4774
• DOI: 10.1016/j.jmatprotec.2018.06.025

[Display omitted] Through different physical and welding experiments, performance of the stepped-plate radiator configuration with varying height and diameter was compared. Arc characteristic measurements show a constriction of the arc column and hence an increase in arc pressure. The variation in arc profile is not linear but a wavelike feature with increasing radiator height. As for radiator diameter, there only exists one wave trough at the fitting curve. Acoustic field simulations verify the maximum acoustic pressure in arc burning zone, consistent with experiments that the maximum constriction degree of welding arc indeed exists in practice. Microstructures of weld metal prepared with ultrasonic vibration indicate the significant grain refinement compared to those without ultrasonic vibration under the same heat input. Ultrasonic wave emitted from the designed radiator generates a large acoustic pressure, which features a concave shape at weld pool zone. Arc-acoustic interaction with a soft reflector of weld pool can be improved by greatly enhancing the acoustic field level through optimizing the stepped-plate radiator configuration.