Single Crystal

The ability to transform the crystal structure of metals in the solid-state enables tailoring their physical, mechanical, electrical, thermal, and optical properties in unprecedented ways. We demonstrate a martensitic phase transformation from a face-centered-cubic (fcc) structure to a hexagonal-close-packed (hcp) structure that occurs in nanosecond timescale in initially near-defect-free single-crystal silver (Ag) microcubes impacted at supersonic velocities.

We have recently published a paper on measurements of the density of geometrically necessary dislocations (GND) associated with wedge indentation of a single face-centered cubic crystal. The deformation field is two-dimensional and there are three effective in-plane slip systems that contribute to the plastic slip. We determine the lower bound on the total GND density with a three micrometer spatial resolution. We also show that in certain regions of the domain, the lower bound on total GND density corresponds to the exact total GND density.

Simulation of crack bifurcation in single crystal nickel base superalloys under mixed mode conditions

PhD position available at the Centre des Matériaux , ParisTech , starting fall 2009.

This 3-year project is fully funded by Mines ParisTech, SNECMA and ONERA.

More details are given in the attached file.