Experimental studies on strength of ultrasonically welded joints of copper wire and sheet used for electrical contacts

Abstract

Recent technological developments in producing electrical newlinecontacts are evolving at a fast rate, resulting in consistent functioning of wide newlinevariety of customer durable products. Due to advent of component newlineminiaturization and improvement in manufacturing light weight portable newlineproducts, there exists a significant demand for superior quality electrical newlinecontacts. The electrical and electronic components used in these products are newlinesubjected to severe operating conditions during the service life of the newlineproducts. Ultrasonic Metal Welding (USMW) has received significant newlineattention in the past few years, and has become more reliable and suitable newlineprocess for producing defect free electrical contacts to be used in these newlineproducts.USMW is an environmentally friendly and rapid solid state newlinejoining process in which similar or dissimilar metals are joined by the newlineapplication of ultrasonic vibrations and adequate pressure at the interface. newlineThe high frequency relative motion between the parts to be welded result in newlineprogressive shearing and plastic deformation between surface asperities. This newlinerubbing action disperses oxides, contaminants and form a sound newlinemetallurgical bond between the two metallic parts.Even though ultrasonic metal welding was invented 70 years newlineago, a comprehensive understanding on the basic mechanism of formation of newlinejoint is far from complete. This lack of understanding is predominantly newlineevident as it relates to the fundamental mechanics of the weld and the newlinecorrelation of weld mechanics to the overall dynamics of the USMW system. newline newline