| Abstract Scope |
Quasicrystals, sometimes, can be regarded as an intermediate state between regular metals (crystal) and metallic glasses (amorphous), in terms of structural and chemical complexity. A long-standing problem, however, significantly impedes practical usage of quasicrystals: steady-state plastic deformation has only been found at high temperatures or under confining hydrostatic pressures; at low and intermediate temperatures, they are very brittle, suffer from low ductility and formability and, consequently, their deformation mechanisms are still not clear. Here, this presentation systematically studies the deformation behavior of icosahedral Al-Pd-Mn and decagonal Al-Ni-Co quasicrystals using a micro-thermomechanical technique over a range of temperatures (25-500 °C), strain rates, and sample sizes accompanying microstructural analysis. Here we show interesting phenomena relevant to small-length scales, including: cracking, serrated flows, diffusion and phase transformation. QC thin films made by co-sputtering is also studied. |