VIBRATION ASISTED PROGRESIVE-DIE MICRO-BLANKING

The progressive development of microprocessors and piezoelectric actuators causes the development of micro-machines and the need for micro parts. For these reasons, accelerated development of microforming technology should be anticipated. This technology is able to ensure high smoothness of the surface created by plastic separation of the material and sharpness of the edges - very difficult to achieve by other methods. Attention should be paid to micro-punching processes that can be used not only to make a hole, but above all to produce an exact shape / blank. This approach defines a further possible difference between micro-blanking and conventional blanking. The difficulty in addition to the so-called the effect of scale is also the need for very little clearance and strict geometric conditions. In micro-blanking processes suggested for the billet production one should take into account relatively large ratios of height to diameter of the punched holes. Currently, micro-blanking processes are carried out in the mass production of electronic components. Within this work micro-blanking tests were carried out on an industrial stand with a progressive die, holes made of aluminum sheet and stainless steel sheet. Punches with piezoelectric vibrators were used. For aluminum sheet, the galling phenomenon was stopped as a result of the self-cleaning process of punches. In the case of stainless sheet metal, a slowing of the build-up process was observed. Structure was determined using TEM tests and a build-up mechanism was suggested, consisting in returning successive shearing of micro-asperities, which leads to the creation of an ultra-fine grained structure.