Formation of Voids in Thin Foil Pure Gold during Plastic Deformation

At the fractured tip of thin foil metals, heavy deformation takes place. At this heavily deformed region, vacancies play an important role. In Al-Pb alloy, lead precipitates are separated into small particles which are considered to be a result of enhanced diffusion by excess vacancies. The production source for these vacancies is considered to be internal nanocracks. In order to test this hypothesis, voids were searched in thin foil aluminum and gold, and void formation was confirmed in gold. It is considered that nanocracks not only become nuclei of voids but also contribute to the growth of voids by glide motion. The ʹʹNanocrack fragmentʹʹ model was proposed in order to account for the slide motion of nanocracks.