Research On The Dynamic Information Measurement And Process Behavior Of Ultrasonic-resistance Hybrid Welding

Non-ferrous metals is widely applied in modern industry，because the non-ferrous metalssuch as copper and aluminum have the characteristics of high electrical and thermalconductivity and coefficient of thermal expansion, welding between them is very difficult.Ultrasonic welding and resistance welding are two commonly used welding methods.Combined with the characteristic of the two welding methods, the research team proposes anew non-ferrous metal welding method: the ultrasonic-resistance hybrid welding. Since thestudy of the method is in the initial stage, we are lack of knowledge of the method, this paperintroduces a detection system of the welding process based on computer technology tostrengthen the understanding of the hybrid welding.The paper builds the data acquisition and analysis system for ultrasonic-resistance hybridwelding. The system includes two aspects: the hardware part and the software part. Thehardware part includes available sensors (voltage sensor, current sensors for both ultrasonicand resistance current, temperature sensor, displacement sensor, etc.), data acquisition cardand signal conditioning circuit. The software part uses the software Labview to program andachieve the functions of data collection, storage, display and processing.Ultrasonic metal welding parameters are optimized using response surface methodology.The optimal process parameters of the ultrasonic welding for0.2mm thick C1100copper arewelding pressure1188N, welding time0.4s and welding amplitude15μm. The paper analyzesthe electrical signals using wavelet analysis method, the result showed that the weldingpressure influenced the voltage and current, the welding pressure increases, the equivalentresistance of the transducer increases, in the case of the stability of the ultrasonic power, theultrasonic voltage increases, the ultrasonic current decreases.With regard to ultrasonic-resistance hybrid welding, the paper analyzes that the currentof the resistance welding influences the ultrasonic signals and finds that the amplitude of theultrasonic voltage and current have gradually increased with the increase of the resistancewelding current. Influenced by resistance welding current, the resonant frequency of the transducer changes, the frequency tracking of ultrasonic power is abnormal, the reactivepower of the ultrasonic power is increased, so that the ultrasonic voltage and current increases;resistance welding current has a tiny effect on vibration. The resistance welding current playsa significant role in promoting temperature rise of the hybrid welding interface. Withoutresistance welding current, the max temperature of the welding area is350degrees, still farfrom reaching the melting point of copper, indicates that the ultrasonic metal welding is asolid-phase connection. The temperature of the weld region and the tool head increases withthe resistance welding current increases, the resistance heat generated by the resistancewelding current is the main reason for the increase of the hybrid welding temperature.