@article{bunget_ngaile_2011, title={Influence of ultrasonic vibration on micro-extrusion}, volume={51}, ISSN={["1874-9968"]}, DOI={10.1016/j.ultras.2011.01.001}, abstractNote={Micro-forming is a miniaturization technology with great potential for high productivity. Some technical challenges, however, need to be addressed before micro-forming becomes a commercially viable manufacturing process. These challenges include severe tribological conditions, difficulty in achieving desired tolerances, and short tool-life due to inability of available die materials to withstand the forces exerted on miniature dies and punches. Some of these problems can be mitigated using ultrasonic technology. The principal objectives of this work were to investigate the possibility of applying ultrasonic vibrations in the micro-forming process, to design a set of tooling for ultrasonic micro-extrusion and to observe experimentally how ultrasonic oscillations influences the forming load and the surface finish. The test results showed a significant drop on the forming load when ultrasonic vibrations were imposed, and also a significant improvement in the surface of the micro-formed parts. Based on the preliminary test results, the study demonstrated high potential for using ultrasonic oscillations as a way to overcome the difficulties brought by the miniaturization.}, number={5}, journal={ULTRASONICS}, author={Bunget, Cristina and Ngaile, Gracious}, year={2011}, month={Jul}, pages={606–616} }
 @book{bunget_ngaile_2008, title={Ultrasonic microforming}, ISBN={9783639000559}, publisher={Saarbrucken: VDM Verlag Dr. Muller}, author={Bunget, C. J. and Ngaile, G.}, year={2008} }