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Strain Mapping in Engineering Materials with High-Energy Synchrotron X-rays

April 18-19, 2005

Location
NSLS Seminar Room, Brookhaven National Laboratory

Introduction
Quantitative understanding of the internal stresses/strain field distribution is fundamental in the design engineering of static and cyclic load-bearing components. The residual stress and strain distribution is difficult to experimentally characterize and is thus often recognized only a posteriori after failure. There has been a gaping hole in the spatial-scale/resolution routinely accessible, by direct or nondestructive methods of strain-field profiling.

The potential of using deeply penetrating high energy (20-250 keV) x-ray scattering to bridge this gap in strain profiling has been recognized for a number of years. The high count rates from small diffraction volumes available using energy dispersive x-ray diffraction (EDXRD) has made it one of the successful new techniques for high-resolution strain field mapping. The initial results of the strain mapping experiments at the NSLS X17B1 beamline have shown that this technique has wide ranging implications in fracture mechanics, fatigue prediction, and FEA model optimization.

To get just a flavor for selected materials science that can be addressed using high spatial resolution, high energy x-ray strain mapping see the following:

Objective

Bringing together key members of the synchrotron community and experts in engineering materials science, the interdisciplinary workshop will discuss and explore the current and potential applications of high-energy x-ray strain mapping to engineering problems, and catalyze new interactions between these fields.

The work shop will assess the user base for the present X17 end station configuration, identify potential funding sources, and determine the viability of additional dedicated experimental hutch space on the X17 beamline. The work shop invitees will be asked to propose potential experiments that define what apparatus and conditions would be conducive to their research. We will also discuss the direction of future strain mapping research and it's potential use at the proposed NSLS-II.

Topics

  • Current X17B1 end station configuration and capabilities (White Beam, Energy Dispersive and Monochromatic, Angle Dispersive)
  • Profiling of the residual stress tensor in materials
  • Mapping of local strain response to in situ stresses, interaction with residual strains, stress concentration effects, strain localization effects etc...
  • Atomic scale stress versus strain measurements and anisotropies in the atomic elastic constants and yield onsets
  • Correlation between the stresses, deformation and fatigue processes of materials
  • Special equipment and sample environments, including in situ, in duty cycle measurements in high temperature materials, thermal barrier, fuel cell, H-storage, and battery research
  • A dedicated hutch in the longer term (2-5) years at NSLS I
  • Impact to NSLS-II

Registration

  • This workshop is free so early registration is strongly encouraged.


  • In addition to submitting a Registration Form for this workshop, all attendees must register in BNL's Guest Information System. Approval, which can take 30 days or more, must be granted prior to attending this workshop.

    Under Department of Energy directives, requests by citizens of Cuba, Iran, Libya, North Korea, Sudan and Syria to attend this workshop require extensive review and approval by many agencies, including the Secretary of the Department of Energy. Approval may take a year or more. If you are still interested in performing work or attending workshops at the NSLS, please contact NSLS User Administration for further information.