Quartz Deformation

We are conducting deformation experiments on Quartz using the D-DIA apparatus. Below are lattice spacings for the quartz (100), (101), and (112) reflections as a function of time during the deformation experiment. The calculated “hydrostatic” d-spacing is shown as a dashed line. The position of each reflection is measured as a function of time during the deformation experiment. D-spacings for the vertical pair of detectors (1 & 2) shrink more than for the horizontal pair (3 & 4), reflecting increasing differential stress.

We use Elastic-Plastic Self-Consistent (EPSC) Models to interpret our diffraction data. EPSC Models assume that ductile deformation is controlled by the motion of dislocations and/or by twinning. We were able to simulate our diffraction data collected at 800°C with an EPSC Model that used only basal and prismatic slip. This is consistent with the slip systems that are thought to operate at this temperature.

useepscmodeling

Figure 1. Schematics of slip systems operating in a hexagonal quartz crystal. We use these slip systems in our EPSC models to model the X-ray synchrotron diffraction data.

 

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101dspacingvstime

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Figure 2. Lattice spacings for the quartz (112) (101) and (100) reflections.

EPSC results

Figure 3. Comparison of  macroscopic stress supported by quartz sample as a function of macroscopic strain.

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