High-temperature plasticity measurements using synchrotron X-rays Book Chapter

Weidner, DJ, Li, L, Durham, W et al. (2005). High-temperature plasticity measurements using synchrotron X-rays . 123-135. 10.1016/B978-044451979-5.50008-9

cited authors

  • Weidner, DJ; Li, L; Durham, W; Chen, J

authors

abstract

  • Synchrotron X-rays coupled with high-pressure deformation facilities have transformed the tools for studying the rheological properties of materials at high pressure and temperature. Successes have come in the last 3 years that have enabled measurements using synchrotron X-rays to define the strain and stress in the sample in a multi-anvil high pressure system with an axial stress capability. The current challenge is to improve the accuracy of stress measurements to 10 MPa and expand the pressure regime for such measurements to over 20 GPa. The new D-DIA device is capable of producing 15 GPa of pressure at 2000 K and simultaneously introducing a differential stress field that can attain steady state flow with strains reading in excess of 50%. Time-dependent flow experiments are among the most demanding of mechanical property measurements. In the traditional deformation experiment, differential stress is monitored by a load cell that indicates the amount of force that is applied to the cylindrical sample. In a similar manner, strain is monitored by displacement of the pistons that are acting on the sample. Diffraction, which defines the elastic changes in lattice spacings, is used to monitor stress, and radiographic images define sample length with time, yielding strain rate. In the new measurement protocol as discussed in the chapter, the stress and strain are measured in the sample directly, with no need for corrections for friction or length changes in soft parts of the cell assembly. X-ray transparent anvils enable diffraction in both the vertical and horizontal directions, providing sufficient information to define differential stress in the sample while the strain rate is monitored by X-ray images. This new tool opens the door to new studies relevant to the processes deep within the Earth, illuminating the dynamics of deep earthquakes and mantle flow. © 2005 Copyright © 2005 Elsevier B.V. All rights reserved.

publication date

  • December 1, 2005

Digital Object Identifier (DOI)

start page

  • 123

end page

  • 135