A Simple Piercing Process Applicable to Brittle Materials

Piercing of brittle sheets, which is difficult to achieve by conventional shearing or drilling, is achieved using a new manufacturing process utilizing the impact compression of a viscoplastic pressure medium, recently proposed by the authors. The impact pressure is analyzed with a linear viscoelastic model to determine optimum working conditions. Under a specific condition the process is shown to be successful in piercing a circular hole through various brittle materials; for example, inorganic glasses, glassy-carbon carbon composite and alumina ceramic sheets. The hole formation process in a glass sheet is examined experimentally and theoretically.