Acoustic horn design for joining metallic wire with flat metallic sheet by ultrasonic vibrations

Pradeep Kumar J,Prakasan K

doi:10.21595/jve.2018.19648

Abstract

Ultrasonic Metal Welding is a green manufacturing technique and one of the most advanced solid state welding processes in which similar or dissimilar metallic components are joined by the application of high frequency vibrations (> 20 kHz) and pressure. Ultrasonic metal welding is accompanied by slip and plastic deformation so that the base metals being welded will not melt and in turn forms a homogenous coalescence of two metals at the joining area so that the joint retains the parent metal properties. The major problem faced by the industries using ultrasonic metal welding process is the poor weld quality and weld strength. The design of acoustic horn or sonotrode plays a dominant role in producing quality welds. The primary function of sonotrode is to vibrate at a level required for welding and also to transmit the vibration energy to the point where welding of metals takes place. For producing quality welds, the vibration energy is to be transmitted to the weld interface without much loss. Therefore, there is a need for accurate design of sonotrodes in ultrasonic metal welding process. This work focuses on designing a stepped sonotrode used for joining metallic wire with metallic sheet based on significant design parameters such as amplitude gain and von Mises stress factor using modal and harmonic analysis. Experimental trials are conducted using the stepped sonotrodes and the effectiveness of the designed sonotrodes is evaluated based on improvement of strength of the joint in tension.

Highlights

Ultrasonic Metal Welding (USMW) is a joining process in which two metallic specimens are joined by the application of ultrasonic vibrations under moderate pressure where the vibrations are applied at the interface between the weld specimens
A systematic study based on the methodology as shown in Fig. 3 is carried out for designing a stepped sonotrode using finite element analysis employing ABAQUS software followed by experimental investigation with the following objectives: 1) To extract the mode shapes and the corresponding natural frequencies of the stepped sonotrodes
An investigation was carried out for designing sonotrodes used for joining metallic wire with a flat metallic surface

Summary

Introduction

Ultrasonic Metal Welding (USMW) is a joining process in which two metallic specimens are joined by the application of ultrasonic vibrations under moderate pressure where the vibrations are applied at the interface between the weld specimens. Amin et al [7] established a computer aided design procedure for selection of sonotrode profile and material based on finite element analysis. The harmonic piezoelectric vibrations of the ultrasonic milling system were simulated by finite element method to study on frequency, amplitude of the vibration and stress distribution. A systematic study based on the methodology as shown in Fig. 3 is carried out for designing a stepped sonotrode using finite element analysis employing ABAQUS software followed by experimental investigation with the following objectives: 1) To extract the mode shapes and the corresponding natural frequencies of the stepped sonotrodes. 2) To determine the dynamic characteristic design parameters such as amplitude gain and von Mises stresses developed in the stepped sonotrodes from finite element analysis.

Design of sonotrode

Finite element analysis of sonotrode

Details of experiments

Findings

Conclusions