Study On Ultrasound Welding Technology Of Light Alloy

Ultrasound metal welding technology realizes solid phase bonding of materials by applying vertical pressure and high frequency vibration in horizontal direction on alloy surface.In recent years,the ultrasonic welding technology has been developed rapidly,and has been used more widely and the welding effect is more reliable.It is mainly used in the welding of dissimilar alloys with different material properties.Ultrasound welding of 6061 aluminum alloys with different thickness and AZ31B light alloy with different thickness was carried out in this paper.Ultrasound welding parts with effective welding joints were obtained by changing welding parameters(welding time,welding pressure,welding amplitude)and material properties(thickness).The mechanical properties of welded joints under different process parameters were investigated by mechanical properties test and hardness test;the formation mechanism of ultrasonic welded joints was explored by micro-morphology analysis;and the instantaneous temperature and stress distribution in the process of ultrasonic welding were explored by simulation analysis.The experimental results show that the same alloy 6061 and aluminum alloy 6061 and magnesium alloy AZ31B have good ultrasonic welding performance,and the effects of welding time,welding amplitude and welding pressure on the mechanical properties of the same alloy ultrasonic welding parts and dissimilar alloy ultrasonic welding parts are parabolic.When the thickness of dissimilar alloy welded parts is 0.3 mm,the optimum parameters are determined as welding amplitude of 10 um,ultrasonic welding time of 0.5 s and ultrasonic welding pressure of 0.4 MPa.The forming process of ultrasonic welded joints can be divided into three stages:weak connection stage,wave-shaped stage and folding stage.The mechanical properties of welded joints in wave-shaped stage are the best.The temperature distribution of ultrasonic welding tends to diverge from the center area to the outside.With the increase of parameters,the temperature value in the center area of the welded parts increases and approaches the melting point temperature of the material,and the maximum stress area gradually approaches the free end of the aluminum alloy from the center area.In this paper,the formation mechanism of ultrasonic welding and the mechanical properties under different process parameters are systematically studied,which provides an important reference for the future research of ultrasonic welding technology.