Influence of sonotrode texture on the performance of an ultrasonic consolidation machine and the interfacial bond strength

Ultrasonic consolidation (UC) has been successfully used in rapid tooling, prototyping and moulding, fibre and sensor embedding, and electronics embedding. To ensure consistent transfer of ultrasonic energy into workpieces, the surface texture of sonotrode is very important. This paper studied the effects and importance of the texture on the UC process. Monolithic Al 3003 H18 samples were consolidated by the alpha ultrasonic weld machine with a worn sonotrode and a newly electrical discharge machining (EDM)-modified sonotrode, and during the process the performance of the UC machine was monitored. Peel tests were conducted for the consolidated samples and the peel strength and linear weld density were compared. As expected, the results showed that UC machine performance improved with the EDM-modified sonotrode. After improving the surface texture of sonotrode, problems such as foil overlap and crinkling were solved. The results showed that an even and rough texture was necessary for the UC machine to achieve a good performance and a high energy transmission efficiency and the surface roughness of sonotrode may have a two-side influence, i.e. increasing void level and introducing more energy, on consolidation. (c) 2008 Elsevier B.V. All rights reserved.