CERAMICS DUCTILE AT LOW-TEMPERATURE

It is generally recognized that ceramics frequently offer advantages over metals in their use, such as chemical resistivity, hardness, wear resistance, high melting temperature, low density and low price. However, the use of ceramics has so far been hampered by their brittleness at low temperature. In this paper, the authors report observations that could open a way to remove these limitations. They observed that conventionally brittle ceramics became ductile, permitting large (approximately 100%) plastic deformations at low temperature, if a polycrystalline ceramic was generated with a crystal size of a few nm. The ductility seems to originate from the diffusional flow of atoms along the intercrystalline interfaces.