|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Fracture Properties and Residual Stresses in Small Dimensions
||Brittle-to-ductile Transition of Quasicrystals at Small Scales: Cracking, Serrated flows, Diffusion and Phase Transformation
||Yu Zou, Jeffrey M Wheeler, Alla S Sologubenko, Pawel Kuczera, Walter Steurer, Johann Michler, Ralph Spolenak
|On-Site Speaker (Planned)
Since quasicrystals were first discovered in the early 1980s, they have been found to possess many unusual and useful properties. A long-standing problem, however, significantly impedes their practical usage: 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, we systematically study 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. Deformation of small-scale quasicrystals reveals a unique mechanism to with crystalline and amorphous metals which is peculiar to quasicrsytals rather than regular crystals and amorphous solids.