A numerical and experimental study of ultrasonic metal welding

Abstract

A numerical and experimental study of ultrasonic metal welding Abstract. Ultrasonic metal welding has been the subject of ongoing research and development, most recently concentrating on metal joining in miniature devices, for example to allow solderfree wire bonding. As well as at the small scale, there are also opportunities to research the joining of thicker sheet metals and to widen the range of similar and dissimilar materials that can be successfully joined using this technology. This study presents the design, characterisation and test of a lateral-drive ultrasonic metal spot welding device. The ultrasonic metal spot welding horn is modelled using finite element analysis (FEA) and its vibration behaviour is characterised experimentally to ensure ultrasonic energy is delivered effectively to the weld coupon. The welding stack and fixtures are then designed and mounted on a test machine to allow a series of experiments to be conducted for various welding and ultrasonic parameters. Weld strength is subsequently analysed using tensile-shear tests. The results show how the weld strength is particularly sensitive to the combination of clamping force and ultrasonic vibration amplitude of the welding tip, but there are optimal combinations of these and also limits that must be clearly identified.

Relation Between Interface Geometry and Tensile Shear Strength of Ultrasonically Welded Joints

“…(a) First, the surfaces are covered with contaminations and oxide layers. Therefore, direct contact between the asperities of surfaces is prevented In conclusion, a physical metal bonding between the juvenile surfaces is mostly considered to be the main reason for the bond formation between the joining partners in US metal welding 15,17,19,21,(23)(24)(25)(26). Mechanical interlocking was also observed to significantly contribute to the bond (Ref 10- 13,15,17,20), especially when the same materials are joined together, e.g., Al/Al joints ( Ref 19).…”

Analysis of horn type waveguide with impulse excitation

“…Since the output amplitude of piezoelectric transducer is very small, the ultrasonic horn is usually designed and operated in harmonization to amplify the output amplitude [1]. Ultrasonic horn could be used for various applications of atomizers [2], welding devices [3], surgery [4], etc. Different shapes of ultrasonic horns, such as Gaussian, exponential, sinusoidal, conical, stepped, catenoidal [5], etc.…”

Formation of aerial standing wave field using ultrasonic sources consisting of multiple stripe-mode transverse vibrating plates

“…Intense acoustic waves have been used in a broad range of fields, including machining, cleaning, welding, and atomization. [1][2][3][4][5][6][7][8][9][10][11][12] However, they are usually applied to liquids or solids. Stripe-mode transverse vibrating plate ultrasonic sources, 13) lattice-mode square vibrating plate ultrasonic sources, 14) and similar devices [15][16][17][18] are used in a variety of applications such as deodorization and vapor agglomeration.…”