Reinforcement of Mg/Ti joints using ultrasonic assisted tungsten inert gas welding–brazing technology

Abstract

Ultrasonic assisted tungsten inert gas welding-brazing technology was developed to refine coarsening columnar a-Mg grains of Mg/Ti joints. In this study, ultrasonic vibration was introduced into molten pool of Mg/Ti joints with frequency of 20 kHz and maximum power of 1?6 kW. The results showed that, with ultrasonic power of 1?2 kW, the morphology of columnar a-Mg grains was refined to approximately equiaxed grains and the average grain size of columnar grains decreased from 200 to ,50 mm. Moreover, the maximum joint strength of joints increased y18?1% to 228 N mm 21 over the joints welded without ultrasonic vibration (193 N mm 21 ).Furthermore, the optimised Mg/Ti joint fractured at base metal zone rather than fusion zone upon tensile-shear loading, indicating that efficient grain refinement was attained. However, welding voids occurred with the ultrasonic power further increased to 1?6 kW, which resulted in the decrease in mechanical properties.

Ultrasonically assisted friction stir welding of aluminium alloy 6061

“…9 Ultrasonic waves have been applied for soldering aluminium. [10][11][12][13] Numerous studies have recently reported on ultrasonic welding and ultrasonic spot welding. [14][15][16][17][18] Ultrasonically assisted friction stir welding (UAFSW) was carried out using an especially adapted conventional friction stir welds for ultrasonic vibration during welding.…”

Auxiliary energy-assisted arc welding processes and their modelling, sensing and control

“…When ultrasound propagates in the medium, it will produce a series of special effects, such as mechanical effects, cavitation, thermal effects and chemical effects, which will affect the physical and chemical properties of the medium [48][49][50]. Recently, researchers have combined UV with traditional welding process, and proposed UV-assisted welding technologies such as UV-assisted arc welding, UV-assisted brazing, UVassisted friction stir welding and other new types of ultrasonic hybrid welding [47,[51][52][53][54]. The combination of UV and traditional arc welding process can enhance the welding process stability or improve the weld quality, which has tremendous application potentials in manufacturing industries [55,56].…”

Vibration assisted welding processes and their influence on quality of welds

“…Workpieces were clamped on a table vibrating longitudinally with the help of an electrodynamic vibrator and welded using manual metal arc welding. Rutile coated mild steel electrodes were used, and the welding current, voltage, energy input, arc length a vibration of workpiece; 15,16,44,[46][47][48][49][50][51][52][53][54][55] b weld pool oscillation; [56][57][58][59]61,[63][64][65][66][67][68][69][70][71][72][73][74][75] c molten droplet oscillation using pulsed current; [76][77][78][79] d oscillation of welding arc; [80][81][82][83][84][85][86][87][88][89][90][91][92] e vibration of electrode…”