Frication stir welding molding device and welding method thereof

Abstract

The invention discloses a frication stir welding molding device and a welding method thereof. The frication stir welding molding device comprises two motors, a stirring shoulder, a stirring head and an ultrasound device. The ultrasound device comprises an ultrasonic generator, a transducer and an amplitude-change pole which are connected in sequence. A through hole is formed in the center of the stirring shoulder, the diameter of the through hole is larger than that of the stirring head, the stirring head penetrates through the through hole, the stirring head and the stirring shoulder are movably connected with the motors, and the amplitude-change pole is fixedly connected with the stirring shoulder. The ultrasound device further comprises a frequency tracker, and the two ends of the frequency tracker are connected with the ultrasonic generator and the transducer respectively. When welding is conducted, the rotation direction of the stirring shoulder is opposite to that of the stirring head, and the rotation speed of the stirring head is 1.5-3 times that of the stirring shoulder. According to the device and the method, occurrence of a hopper type temperature field is avoided in the welding process, and uniformity of welded joint structures is guaranteed.

Description

Technical field [0001] The invention relates to the technical field of metal welding, in particular to a friction stir welding forming device and a welding method thereof. Background technique [0002] Friction welding is a method that uses the heat generated by the mutual movement and friction of the end faces of the plates to make the ends reach a thermoplastic state, and then quickly upset to complete the welding. Friction stir welding has its unique advantages in welding of plates. However, because the existing technology uses the stirring head and the stirring shoulder to rotate simultaneously, the upper surface of the welding piece not only friction and heat with the stirring head, but also friction and heat with the stirring shoulder, forming in the welding zone The “funnel-type” temperature field with high top and low bottom, high surface temperature, low deep layer temperature, the bottom layer of the welding zone has not yet reached the plastic state required for weldin...

AI Technical Summary

Problems solved by technology

Friction stir welding has its unique advantages in sheet metal welding. However, due to the synchronous rotation of the stirring head and the stirring shoulder in the existing technology, the upper surface of the weldment not only generates heat by friction with the stirring head, but also generates heat by friction with the stirring shoulder. The upper and lower "funnel" temperature field, the surface temperature is high, the deep layer temperature is low, and the bottom layer of the welding zone has not yet reached the plastic state required for welding, making it difficult to weld the bottom layer, or at the expense of overheating the upper layer structure, to improve the lower plate. temperature, and some alloy plates have strict restrictions on welding temperature and time, this phenomenon is more prominent in thick plate welding, therefore, it is urgent to propose a method to solve the "funnel" temperature field existing in friction stir welding question

[0003] In addition, since the resonance frequency of the ultrasonic vibration device is sensitive to factors such as external loads and thermal loads, changes in these factors will cause changes in the resonance frequency of the ultrasonic vibration device, resulting in detuning or stoppage of the ultrasonic vibration device.

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