抄録
High-density nanocrystalline (n-) gold with almost the full density is prepared by a gas-deposition method. The Young's modulus of the high-density n-Au is comparable with that of conventional polycrystalline Au, while an anelastic strain as large as the elastic strain is observed in the quasi-static test. The hardness and the tensile yield stress are about three time larger than those of the polycrystalline Au. Beyond a certain applied stress, however, the steady-state creep rate showed a steep increase. These characteristic mechanical properties are owing to the grain boundary regions with the much increased volume fraction and provide good workability of n-Au at elevated stresses. It is noted that n-Au is chemically stable and a potential candidate for a structured material of micromachines.
